Image reading apparatus and media conveying apparatus

An image reading apparatus according to the present invention comprises an image reading unit arranged on a conveying path of a first medium and reading an image on the first medium, a conveying unit conveying the first medium and a second medium to the image reading unit, a width of the second medium being smaller than the first medium, and guide portions guiding the second medium introduced from a discharge port along the conveying path.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image reading apparatus for, for example, an image scanner, copying machine, or facsimile apparatus.

2. Description of the Related Art

As an image reading apparatus, for example, an ADF (Auto Document Feeder) type image reading apparatus, which can successively read stacked sheet-like media, is available. The ADF type image reading apparatus separates sheet-like media each having a predetermined size one by one, and automatically and successively feeds the separated media to execute image reading processing. Hence, the ADF type image reading apparatus can automatically convey and read media in large quantities.

On the other hand, media such as thin media, film-like media, or cards, which are different from generally used paper sheets, are often not suited to automatic feeding. Hence, the following apparatus has been proposed. That is, in this apparatus, media, which are not suited to automatic feeding, are manually fed from a discharge port side, and a conveying direction of a conveying system is switched to an opposite direction, so as to allow to introduce the cards and to read their images (for example, Japanese Patent Laid-Open Nos. 9-284478 and 2008-270954).

A size in a widthwise direction of the discharge port of the image reading apparatus is designed to be able to discharge media having a maximum size, which is planned to be used in that image reading apparatus. For this reason, for media having a small size such as cards, the width of the discharge port is often too large. As a result, when a medium having a small size is manually inserted from the discharge port, since it is skewed, a problem is posed for discharging of that medium, and an image cannot often be appropriately read.

SUMMARY OF THE INVENTION

The present invention provides a mechanism for preventing any skew of a medium having a small size such as a card when such medium is introduced from a discharge port.

According to one aspect, there is provided an image reading apparatus comprising: an introduction port used to introduce a first medium; a discharge port used to discharge the first medium; an image reading unit configured to read an image on the first medium, the image reading unit being arranged on a conveying path of the first medium, which extends from the introduction port to the discharge port; a conveying unit configured to convey the first medium from the introduction port to the discharge port, and to convey a second medium, a width of which is smaller than the first medium and which is introduced from the discharge port, to the image reading unit, so as to read an image on the second medium by the image reading unit; and guide portions configured to guide the second medium introduced from the discharge port along the conveying path, the guide portions being arranged along a conveying direction of the second medium to oppose side surface portions in a widthwise direction of the second medium.

DESCRIPTION OF THE EMBODIMENTS

First Embodiment

FIG. 1Ais a perspective view showing the outer appearance of an image reading apparatus A according to an embodiment of the present invention,FIG. 1Bis a schematic sectional view of the image reading apparatus A taken along a line I-I inFIG. 1A,FIG. 2is a plan view of the image reading apparatus A, andFIG. 3Ais a schematic sectional view of the image reading apparatus A taken along a line II-II inFIG. 1A.

The image reading apparatus A includes a conveying/reading portion10which includes a mechanism for conveying a first medium M1and second medium M2, and reading images on the conveyed media, and housing portions20and21, which are disposed on two sides of the conveying/reading portion10. In the housing portion20, a driving source or portion155of a conveying mechanism15which conveys the media M1and M2is disposed. The driving portion155includes, for example, a motor, and a transmission mechanism for transmitting an output of the motor to driving shafts of rollers (to be described later) and the like. The housing portion21houses, for example, a control circuit and the like.

In this embodiment, the medium M1is a sheet-like medium, and is, for example, a paper sheet. In this embodiment, the medium M2is a medium which has a width smaller than the medium M1and a thickness larger than the medium M1, and is, for example, a plastic card.

To one end portion of the conveying/reading portion10, a feed tray111is arranged to be free to open/close. In a state in which this feed tray111is open, an instruction portion11used to introduce the medium M1is open to the upper end portion side of the image reading apparatus A. On the other hand, a discharge port12used to discharge the medium M1is formed on the other end portion of the conveying/reading portion10. A portion of this discharge port12is commonly used as an introduction port (insertion port) used to, for example, manually introduce the medium M2, and a discharge port of the medium M2after an image is read by a reading unit. Also, this discharge port12includes a discharge port12aused to discharge the medium M1, and a discharge port12b, a vertical height of which is increased compared to that of the discharge port12a, and which is used to introduce and discharge the medium M2.

Since the vertical height of the discharge port12bis increased compared to the discharge port12a, a merit that allows the user to easily recognize an introduction position of the medium M2can be provided. Also, the discharge port12bis formed with tapers12b, whose opening area is gradually reduced at its upper, lower, right, and left edge portions, and allows easy insertion of the medium M2from the discharge port12b.

To the introduction portion11, a feed port (introduction port)110used to introduce the medium M1into the conveying/reading portion10is arranged.

Also, in this embodiment, an automatic document feeder (ADF) is disposed. The ADF includes the feed tray111on which a plurality of media M1are stacked, a feed roller112, and a separation pad113.

The feed tray111includes rotary hinge portions111a, and is configured to be foldable on the upper surface of the conveying/reading portion10, and is set in an open state when it is used, as shown inFIGS. 1A and 1B. The feed roller112is rotated by the driving portion155, and feeds a lowermost medium M1of those stacked on the feed tray111.

The separation pad113is arranged to be in contact with an outer surface of the feed roller112. By taking the medium M1fed upon rotation of the feed roller112into a gap between this separation pad113and the outer surface of the feed roller112, the medium M1can be automatically separated and fed one by one.

The feed roller112and separation pad113are arranged only in a central portion in the widthwise direction (right-and-left direction) of the conveying/reading portion10, and is not arranged in a region behind the discharge port12b, as shown inFIG. 3A. This is to avoid the medium M2from interfering with the feed roller112and separation pad113at the time of reading of the medium M2.

A conveying path (conveying space) RT where the media M1and M2are conveyed is formed of a wall portion156which forms a top wall of the path, and a wall portion157which forms a bottom wall of the path. The wall portions156and157are disposed over nearly the entire region of the conveying/reading portion10.

Referring mainly toFIG. 1B, the conveying portion or mechanism15includes, as a conveying mechanism of the medium M1, driving shafts152aand154aand driven shafts151aand153a, which extend in the widthwise direction (right-and-left direction) of the conveying/reading portion10. The conveying mechanism of the medium M1includes a conveying roller pair including a driving roller152arranged on the driving shaft152aand a driven roller151arranged on the driven shaft151a, and a conveying roller pair including a driving roller154arranged on the driving shaft154aand a driven roller153arranged on the driven shaft153a.

One or a plurality of rollers are arranged as each of these rollers in the widthwise direction (right-and-left direction) of the conveying/reading portion10, and enter the conveying path RT via openings formed in the wall portion156or157. The medium M1, which is introduced by the ADF from the introduction portion11, is conveyed by these conveying roller pairs through the conveying path RT to the discharge port12(12a) in a direction indicated by an arrow inFIG. 1B, and is discharged.

In the middle of the conveying path RT extending from the introduction portion11to the discharge port12, image reading units13and14are disposed. The image reading units13and14read images from the media M1and M2, which are conveyed through the conveying path RT, and extend over nearly the entire region in the widthwise direction (right-and-left direction) of the conveying/reading portion10. For example, each of the image reading units13and14reads an image as image data by optically scanning the image, and converting the scanned image into an electrical signal, and includes a light source such as an LED, image sensor, lens array, and the like.

The image reading unit13is disposed on the top portion side of the conveying path RT, and the image reading unit14is disposed on the bottom portion side of the conveying path RT, so that the image reading unit13reads an upper face of the conveyed medium M1or M2, and the image reading unit14reads a lower face of the conveyed medium M1or M2. This embodiment adopts a configuration in which both the faces of the medium M1or M2are read. Alternatively, a configuration in which one of the image reading units13and14is disposed to read one face may be adopted. Note that an image reading timing of the medium M1in the image reading units13and14is detected by a sensor30awhich is disposed on the upstream side of the image reading units13and14. The sensor30ais, for example, an optical sensor.

In this case, upon conveying the aforementioned medium M1from the introduction portion11to the discharge port12, the medium M1is inflected by a bent portion RTw between the feed roller112and the conveying roller pair (driving and driven rollers152and151), and is conveyed. For this reason, it is difficult to convey a card-like medium (especially, a thick medium, a medium having a high rigidity, or the like). Hence, the medium M2is introduced from the discharge port12b, is conveyed to the image reading units13and14to read images, and is discharged from the discharge port12bagain. By bending the conveying path RT of the medium M1in this way, the apparatus height, depth, and the like in the image reading apparatus A can be reduced, thus attaining downsizing of the overall apparatus. A conveying mechanism of the medium M2of the conveying portion15will be described below mainly with reference toFIG. 3A.

The conveying portion15includes, as a conveying mechanism of the medium M2, a conveying roller pair including a driving roller152′ arranged on the driving shaft152aand a driven roller151′ arranged on the driven shaft151a, and a conveying roller pair including a driving roller154′ arranged on the driving shaft154aand a driven roller153′ arranged on the driven shaft153a.

More specifically, the driving portion155which configures a conveying unit includes a first conveying mode (normal conveying mode) for conveying a medium from the introduction portion11toward the discharge port12, and a second conveying mode (reverse conveying mode) for conveying a medium from the discharge port12btoward the image reading units13and14, and can control to switch the two modes.

For example, in this embodiment, upon introduction of the medium M2into the discharge port12b, the medium M2is conveyed in the reverse conveying mode, and after the medium M2has passed a region facing the image reading units13and14, the reverse conveying mode can be switched to the normal conveying mode (to be also referred to as “switchback conveyance” of the medium M2hereinafter). Note that in the switchback conveyance of the medium M2, the medium M2may be continuously conveyed or may be temporarily stopped upon switching over the conveying direction.

In this embodiment, a sensor31used to detect arrival and passage of the medium M2is arranged on the introduction portion11side of the image reading units13and14and, more specifically, between the image reading units13and14and the conveying roller pair (driving and driven rollers152and151).

The sensor31is used to detect a reverse conveying timing (switchback conveyance timing) so as to discharge the medium M2read by the image reading unit13or14from the discharge port12bat the time of conveyance of the medium M2. Note that images on both the faces of the medium M2may be read in one of a forward and backward paths, or images may be separately read face by face in both the forward and backward paths.

In this embodiment, as the rollers151′ to154′, those having a smaller diameter than that of the rollers151to154are used. This is to consider the fact that the medium M2is thicker than the medium M1. However, as both of these rollers, those having the same diameter may be used.

Note that at least surface layers of the rollers151′ to154′ are preferably formed of a material (cushioning material such as low-hardness rubber, elastomer, or sponge) softer than the rollers151to154. This is to assure an appropriate conveying force while appropriately absorbing thickness variations caused by, for example, types of media M2.

Taking a credit card as an example of the medium M2, when text regions have embossed portions, these embossed portions are absorbed by elastic deformations of the rollers151′ to154′, thereby preventing the medium M2from being skewed due to the embossed portions which locally serve as resistive regions at the time of conveyance. In such case, the rollers151′ to154′ having the same diameter as the rollers151to154may be used.

In this embodiment, the conveying mechanism of the medium M1and that of the medium M2commonly use the driving shafts152aand154aand driven shafts151aand153a, thus also commonly using the driving portion155. However, a conveying portion of the medium M1and that of the medium M2may be independently configured.

When the user manually introduces the medium M2, if the introduction direction is improper, the medium M2may be conveyed while being skewed. In order to prevent such skew, the following arrangement is equipped.

In this embodiment, in a region behind the discharge port12b, the wall portions156and157respectively have concave portions156aand157a, as shown inFIG. 3A. The concave portions156aand157ahave a right-and-left width (which is slightly wider than that of the medium M2) corresponding to that of the medium M2, and extend in a depth direction (conveying direction of the medium M2).

The concave portion156ais concave upward, and the concave portion157ais concave downward. A concave depth is set according to the thickness of the medium M2.FIG. 3Bshows a relationship among a thickness t of the medium M2, a height K1in an up-and-down direction of a portion formed with the concave portions156aand157aof the conveying path RT, and a height K2in the up-and-down direction of a portion excluding the concave portions156aand157aof the conveying path RT. Note that the discharge port12aalso has the height K2.

Then, the relationship of these thickness and heights meets K2<t<K1. With this relationship, when the user inserts the medium M2into the discharge port12, it is difficult to insert it into a portion other than the discharge port12b, thus urging the user to insert the medium M2at a proper position.

Then, inner side surfaces of the concave portions156aand157aform regulation wall portions SW, which are disposed along the conveying direction of the medium M2to face side surface portions of the medium M2in the widthwise direction, and guide the medium M2which is introduced from the discharge port12binto the conveying path RT, as shown inFIG. 3C. The regulation wall portions SW serve as guide portions which prevent any skew of the medium M2. The regulation wall portions SW do not pose any problem for conveyance of the medium M1since they exist above or below a passing position of the medium M1in the relationship with the medium M1. In this embodiment, end portions of the concave portions156aand157aextend up to the discharge port12, thus configuring the discharge port12b.

Note that in this embodiment, the concave portions156aand157aare respectively formed in the wall portions156and157. Alternatively, a concave portion may be formed in one of the wall portions to form the regulation wall portion SW only on the upper or lower side.

The operations of the image reading apparatus A upon reading of images on the medium M2will be described below with reference toFIG. 4. In this embodiment, an opening16is formed in a rear portion of the conveying/reading portion10, so that the medium M2is linearly conveyed and is temporarily projected from the opening16at the time of reading of images on the medium M2. This contributes to downsizing of the image forming apparatus A.

More specifically, as shown inFIG. 2, for example, in this embodiment, a length D in the depth direction of the image reading apparatus A is substantially equal to a length D′ in the lengthwise direction of the medium M2. Also, the conveying path RT of the medium M2includes a straight path, which is formed to extend from the discharge port12bthrough a portion of the conveying path of the medium M2a slit (which is a conveying path dedicated to the medium M2, and is a saving area for switchback conveyance in this embodiment) open to the bent portion RTw. For example, this slit is open, as the opening16, to the rear portion (rear surface) of the image reading apparatus A in this embodiment.

For this reason, in a state in which after the medium M2is introduced from the discharge port12b, the leading end of the medium M2reaches the rear end portion of the image reading apparatus A, the entire medium M2is temporarily housed inside the image reading apparatus A. After that, when the trailing end portion of the medium M2has passed the sensor31, the medium M2goes into the slit, and the driving portion155is switched to perform switchback conveyance.

At this time, the leading end portion side of the medium M2temporarily projects from the opening16. At this time as well, since the rear portion side of the medium M2is guided by the regulation wall portions SW, its movement in the widthwise direction is substantially regulated. Thus, even in the switchback conveyance, any skew of the medium M2can be effectively prevented.

As described above, in this embodiment, as the regulation wall portions used to prevent any skew of the medium M2, the wall portions (conveyance guides of the medium M2) are arranged on at least portions corresponding to the discharge port12bside and its opposite side (opening16side) of the image reading units13and14in the conveying path RT of the medium M2. Thus, the image reading apparatus A of this embodiment can attain switchback conveyance of the medium M2by commonly using a portion of the conveying path, and can effectively prevent any skew of the medium M2, while allowing to convey the medium M1, thus improving image reading quality.

InFIG. 4, reference numeral ST1denotes a state in which the user introduces the medium M2into the discharge port12b. The user can easily introduce the medium M2into the discharge port12bto have a correct posture using guidance of the regulation wall portions SW. Introduction of the medium M2is detected by the sensor30. The sensor30is, for example, a reflection type optical sensor. When the sensor30detects introduction of the medium M2(arrival of the leading end portion side of the medium M2in practice), the driving rollers154′ and152′ are rotated to convey the medium M2in a direction of an arrow, so that the medium M2introduced into the discharge port12bis conveyed to the image reading units13and14. At the time of conveyance, a movement in a surface direction of the medium M2is regulated due to the presence of the regulation wall portions SW, thus effectively preventing any skew of the medium M2.

When the medium M2passes through the image reading units13and14, the image reading units13and14read images on the obverse and reverse faces of the medium M2. Reference numeral ST2denotes a state in which the reading operations is complete. A portion of the medium M2projects from the opening16.

Upon completion of the reading operations, the driving rollers154′ and152′ are rotated in a reverse direction to convey the medium M2in the reverse direction. Whether or not the reading operations are complete can be judged using, for example, the reading results of the image reading units13and14. Reference numeral ST3denotes a state in which the medium M2is conveyed in the reverse direction. Note that the image reading operations may be made in the middle of this conveyance in the reverse direction.

Reference numeral ST4denotes a state in which the medium M2is being discharged from the discharge port12b. When the medium M2is discharged from the discharge port12b, processes as one unit end.

In this manner, according to this embodiment, the regulation wall portions SW can prevent any skew of the medium M2, and can be prevented from interfering with the medium M1at the time of conveyance of the medium M1.

Second Embodiment

When the image reading units13and14are fixed, an interval between their reading surfaces is that which allows the medium M2thicker than the medium M1to pass through it. For this reason, the reading surfaces of the image reading units13and14are often separated away from the obverse and reverse faces of the medium M1, and a sharper image is often difficult to obtain. Hence, a movable mechanism which allows the image reading units13and14to be movable so as to decrease and increase the interval between the reading surfaces of the image reading units13and14may be arranged.FIG. 5shows an example of such movable mechanism.

Referring toFIG. 5, the image reading unit13is arranged to be vertically displaceable by guide plates131, and is supported by an elastic member132such as a coil spring in a suspended state. The image reading unit14is arranged to be vertically displaceable by guide plates141, and is biased upward by an elastic member142such as a coil spring. Thus, the image reading unit13is movable in a direction to be separated away from the conveying path according to the thickness of the medium M2.

Note that it is desirable to respectively set the suspended position of the image reading unit13by the elastic member132and the biased position of the image reading unit14by the elastic member142at the two-end portion side in the lengthwise direction of the image reading units. This is because the unit reading surfaces can be efficiently brought into contact with the medium M2at the time of conveyance of the medium M2at the one-end portion side of the image reading units. Also, slopes13aand14aare respectively formed on the two end portions of the image reading units13and14in the conveying direction of the medium M1or M2.

Normally, a state ST11is set. In this state, the image reading unit13is located at its lowermost position, and the image reading unit14is located at its uppermost position, and the interval between the reading surfaces of the image reading units13and14is a narrow interval within a range that allows the medium M1to pass through it. Note that stoppers which restrict the lowermost position of the image reading unit13and the uppermost position of the image reading unit14may be arranged.

At the time of passage of the medium M2, the slopes13aand14acontact the medium M2, so that the image reading unit13moves upward, and the image reading unit14moves downward, thus increasing the interval between the reading surfaces in correspondence with the thickness of the medium M2. Upon completion of passage of the medium M2, the image reading units13and14return to the state ST11again by the elastic members132and142.

In this manner, according to this embodiment, since the interval between the reading surfaces of the image reading units13and14changes in correspondence with the media M1and M2, more suitable image reading operations can be attained. Note that in this embodiment, the image reading units13and14are respectively configured to be vertically movable. Alternatively, only one image reading unit may be configured to be vertically movable.

Third Embodiment

In the first embodiment, the regulation wall portions SW are formed using the wall portions156and157, but they may be formed using another guide member.FIG. 6Ais a perspective view showing the outer appearance of an image reading apparatus B according to another embodiment of the present invention, andFIG. 6Bis a perspective view showing the outer appearance of a regulation member40.FIGS. 7A and 7Bare explanatory views of the operations of the regulation member40, and are schematic sectional views of the image reading apparatus B taken along a line IV-IV inFIG. 6A. In these figures, the same reference numerals denote components of the image reading apparatus B, which correspond to those of the image reading apparatus A, a description thereof will not be repeated, and different components will be explained.

In this embodiment, a height in an up-and-down direction of the discharge port12and conveying path RT is decided with reference to the thickness of the medium M2, and the same height is set over the entire region.

The regulation member40includes a roughly U-shaped main body portion41having a top portion41band a pair of side portions41a, and a tab portion42which extends forward from the top portion41b, and serves as a guide member. The main body portion41is formed with a notch43used to prevent any interference between the driven roller153′ and driven shaft153a, and the regulation member40. Also, slopes41a′ are formed on front and rear portions of the lower ends of the side portions41a.

The regulation member40is arranged inside the conveying/reading portion10except for its tab portion42, and is vertically displaceable. The tap portion42externally projects from an opening10aformed in the front surface of the conveying/reading portion10, and is operable by the user. A height in the up-and-down direction of the opening10ais set to allow a vertical displacement of the regulation member40.

FIG. 7Ashows a state in which the regulation member40is located at a lower guide position.FIG. 8Ais a schematic sectional view around the regulation member40taken along a line V-V inFIG. 7A. The regulation member40is in a state in which its slide portions41apass through slits formed in the wall portion156and land on the wall portion157. Inner side surfaces of the slide portions41aform the regulation wall portions SW. At this guide position, the regulation wall portions SW guide the medium M2which is introduced from the discharge port12into the conveying path RT, and prevent its skew.

Note that grooves G are formed in the wall portion157, and the lower ends of the side portions41acan enter the grooves G, as shown inFIG. 8B. Thus, a situation in which gaps are formed between the lower ends of the side portions41aand the wall portion157, and the regulation wall portions SW do not guide the medium M2can be prevented more reliably.

In this embodiment, the regulation wall portions SW are arranged in a region between the discharge port12and conveying roller pair (rollers153′ and154′), and prevent any skew of the medium M2within this range. Therefore, a guide length of the medium M2is smaller than the first embodiment. However, a skew of the medium M2is usually caused by an improper direction of the medium M2when the user introduces the medium M2. Hence, even when the regulation wall portions SW are arranged within the range of this embodiment, they have a given effect to prevent any skew of the medium M2.

FIG. 7Bshows a state in which the regulation member40is located at an upper retracted position. The side portions41aof the regulation member40roughly exit from the conveying path RT, and do not disturb conveyance of the medium M1which passes through the conveying path RT.

The user moves the regulation member40vertically while pinching the tab portion42to displace the regulation member40to the retracted position inFIG. 7Bwhen the medium M1is automatically fed by the ADF, and to the guide position inFIG. 7Awhen the medium M2is manually introduced from the discharge port12. Note that even when the user forgets to displace the regulation member40to the retracted position at the time of reading of the medium M1, in case of this embodiment, the medium M1contacts the slopes41a′ to push up the regulation member40, thus preventing the medium M1from being jammed.

As described above, according to this embodiment, the regulation wall portions SW can prevent any skew of the medium M2, and can be prevented from interfering with the medium M1at the time of conveyance of the medium M1.

Note that an elastic member such as a coil spring, which always biases the regulation member40, may be arranged to normally locate the regulation member40at the retracted position. Also, in this embodiment, the regulation member40is manually vertically moved. Alternatively, an electric actuator which automatically moves the regulation member vertically may be arranged.

Fourth Embodiment

The third embodiment and the second embodiment can be combined with each other. In terms of changing the interval between the reading surfaces of the image reading units13and14in correspondence with the media M1and M2, as described in the second embodiment, an interlocking mechanism which displaces at least one of the image reading units13and14to be interlocked with the displacement of the regulation member40may be arranged.

FIGS. 9A and 9Bare explanatory views of an interlocking mechanism50between the regulation member40and the image reading unit13. The interlocking mechanism50includes a rack51arranged on the regulation member40, a rack52arranged on the image reading unit13, and a pinion53which is rotatably supported between the racks51and52and meshed with them. Note that the image reading unit13can be arranged to be vertically displaceable by, for example, the guide plates131shown inFIG. 5.

With this interlocking mechanism50, when the regulation member40moves upward, the image reading unit13moves downward. When the regulation member40moves downward, the image reading unit13moves upward.

Then, a positional relationship between the regulation member40and the image reading units13and14is set as follows. That is, when the regulation member40is located at the retracted position, the image reading unit13is located at a medium M1reading position in the vicinity of the image reading unit14, and when the regulation member40is located at the guide position, the image reading unit13is located at a medium M2reading position separated from the image reading unit14. In this manner, the interval between the reading surfaces of the image reading units13and14can be changed in correspondence with the media M1and M2.

Fifth Embodiment

In the third embodiment, the regulation member40is displaceable between the guide position and retracted position by its vertical translation. Alternatively, the relation member may be displaceable by means of swinging.FIGS. 10A and 10Bare explanatory views of a regulation member60, and are schematic sectional views of an image reading apparatus C using the regulation member60.FIG. 11is an explanatory view of the regulation member60, and shows an overview of a swinging mechanism. Different components from the example of the third embodiment will be described below.

Referring mainly toFIG. 11, the regulation member60is arranged swingably about an axis parallel to a direction perpendicular to the conveying direction of the medium M1. More specifically, in this embodiment, a pair of regulation members60are used, and each regulation member60has a plate-like shape which includes a shaft hole61in which the driven shaft153ais rotatably inserted, and which extends from the shaft hole61toward the discharge port12side. Also, each regulation member60is formed with a slope63at a position corresponding to a rear end portion in the conveying direction of the medium M1.

On two sides of the shaft hole61, stoppers62, which restrict movements of the regulation member60in the axial direction of the driven shaft153a, are attached to the driven shaft153a. The pair of regulation members60are attached to the driven shaft153ato be spaced apart by a distance according to the width in the right-and-left direction of the medium M2, and their inner side surfaces configure the regulation wall portions SW.

Note that this embodiment uses the pair of regulation members60. Alternatively, these regulation members may be integrated into a single member. Also, the driven shaft153ais commonly used as a swinging central shaft. Alternatively, a dedicated swinging central shaft may be arranged in addition to the driven shaft153a.

The operation of the regulation members60will be described below with reference toFIGS. 10A and 10B. Unlike in the third embodiment, the regulation members60are entirely arranged inside the conveying/reading portion10since they are not manually operated by the user.

In a normal state, the regulation members60are located at a guide position shown inFIG. 10Aas a result of a swing motion due to their self weights. In this state, the regulation members60pass through slits formed in the wall portion156, and land on the wall portion157. This state is just the same as that of the side portions41of the regulation member40shown inFIG. 8A. The regulation wall portions SW configured by the inner side surfaces of the regulation members60guide the medium M2, which is introduced from the discharge port12into the conveying path RT, and prevent its skew.

When the medium M1is conveyed, and is discharged from the discharge port12, the leading end portion of the medium M1contacts the slopes63to cause a swing motion of the regulation members60, and the regulation members60automatically move to a retracted position shown inFIG. 10B. That is, when a clockwise swinging force inFIG. 10Bgenerated by a conveying force of the medium M1exceeds a counterclockwise swinging force inFIG. 10Bgenerated by the self weights of the regulation members60, the regulation members60automatically move to the retracted position. Respective arrows shown inFIG. 11indicate the conveying direction of the medium M1and swinging direction of the regulation members60.

As described above, according to this embodiment, the regulation wall portions SW can prevent any skew of the medium M2and can be prevented from interfering with the medium M1at the time of conveyance of the medium M1. Note that it is preferable to combine this embodiment with the second embodiment and the arrangement example (grooves G) shown inFIG. 8B.

Sixth Embodiment

The first to fifth embodiments of the present invention have been described. However, the present invention is not limited to the aforementioned first to fifth embodiments, and respective embodiments may be combined with each other.

Furthermore, the aforementioned first embodiment and the like have explained the case in which the medium M2is conveyed by the switchback conveyance. Of course, the present invention is not limited to this. For example, the medium M2may be introduced from the discharge port of the medium M1, and may be discharged to the apparatus rear surface side (opening16).

In the aforementioned first embodiment and the like, the medium M2temporarily projects to the apparatus rear surface side when it is conveyed by the switchback conveyance. Of course, the present invention is not limited to this. For example, a sufficient region may be assured between the end portions of the image reading units and the apparatus rear surface, so as not to project the medium M2from the apparatus rear surface.

Moreover, when the medium M2has a rectangular shape (for example, a credit card), in place of inserting the medium M2from one end portion in its lengthwise direction in the first embodiment and the like, for example, the medium M2may be inserted from one end portion in its widthwise direction, that is, from its long side, and may be conveyed to execute image reading operations.

In this case, the medium M2can be prevented from projecting from the apparatus rear surface, and the switchback conveyance can be realized without increasing the size of the apparatus. Also, the switchback conveyance can be prevented from being disturbed when the medium M2collides against an obstacle on the apparatus rear surface side. In addition, since the need for forming the projection opening of the medium M2on the apparatus rear surface can be obviated, the rigidity, durability, and the like of the apparatus can also be improved (for example, entrance of dust or the like into the apparatus can be prevented).

Seventh Embodiment

An image reading apparatus according to the seventh embodiment of the present invention will be described below.

The arrangement of an image reading apparatus1010of this embodiment will be described first with reference toFIG. 12.

Referring toFIG. 12, sheet-like media (to be referred to as sheet media hereinafter) S such as paper sheets or films to be read are placed on a tray1001. A feed portion (introduction port)1002as a first medium feed portion separates a plurality of sheet media S one by one using a separation portion1021, and each sheet medium is conveyed by a feed roller1022to a conveying portion1004. A bent portion1031is formed on a conveying path1003along which the sheet medium S is conveyed. Such bent portion1031is formed to attain downsizing of the image reading apparatus1010. That is, in order to form the conveying path1003without any bent portion1031, a size of the apparatus has to be increased. Note that a sheet medium having a relatively low rigidity is conveyed while it deforms along the bent portion1031.

Also, on the conveying path1003, a saving portion1032, which is a portion of the conveying path1003that extends from a discharge portion (discharge port)1006as a second medium feed portion beyond the conveying portion1004and can receive the leading end portion of a sheet, is arranged. Note that an end portion of this saving portion1032may be open to the rear surface of the apparatus main body like in this embodiment or the saving portion1032may be arranged only inside the apparatus main body without being open to the outside of the apparatus.

The conveying portion1004includes a first conveying roller pair1041. Also, the discharge portion1006includes a second conveying roller pair1061and guide unit1064, and discharges the sheet medium S conveyed from the conveying portion1004to outside the apparatus. The guide unit1064includes right and left rib portions1641, which are disposed to be perpendicular to a conveying direction and to be separated by about 5 mm from a card width, so as to close the conveying path1003. The guide unit1064includes its rotary fulcrum portions on an upper portion of the conveying path1003, and is fixed to be swingable in the conveying direction.

The image reading apparatus1010includes a driving portion (not shown) which rotates the first and second conveying roller pairs1041and1061in normal and reverse directions.

An image reading portion1005includes a first image reading unit1051and second image reading unit1052which have area image sensors such as a CCD or C-MOS, and are disposed at upper and lower positions to sandwich the conveying path1003between them. The first and second image reading units1051and1052are arranged between the first conveying roller pair1041and the second conveying roller pair1061on the conveying path1003, and can read an image on a first face of a passing document and an image on a second face as a reverse face of the first face. A detection sensor1009is arranged between the image reading portion1005and first conveying roller pair1041, and detects the presence/absence of a passing sheet medium.

A discharge sensor1100is arranged in the vicinity of the discharge portion1006, and detects the presence/absence of a passing sheet medium. In this case, the sensor1100is described as a discharge sensor, but it also serves as an insertion detection sensor for a sheet medium such as a card, as will be described in detail later. Note that the image reading apparatus1010of this embodiment can feed documents respectively from the feed portion1002and discharge portion1006. When a document is fed from the discharge portion1006, the user inserts a sheet medium such as a card from a gap between the pair of rib portions1641arranged on the guide unit1064. That is, the guide unit1064has not only a role as a marker (a target of a card insertion portion) in terms of the outer appearance when the user inserts a sheet medium such as a card into an opening of the discharge portion1006, but also a role of guiding an insertion direction of the sheet medium to restrict a movement of the sheet medium in a direction perpendicular to its insertion direction (a widthwise direction of the sheet medium). Therefore, by arranging the guide unit1064at an entrance of the conveying path where a sheet medium such as a card is to be inserted, the guide unit1064defines an insertion position of the sheet medium such as a card, and the sheet medium such as a card can be linearly inserted without being skewed and can be taken into the image reading apparatus1010. Note that in this embodiment, the guide unit1064has a color different from its surrounding members (for example, the discharge portion1006and its neighboring members), and is easily visually confirmed (discriminated) as a card insertion port in terms of the outer appearance. A size of the guide unit1064between the pair of rib portions1641is decided in correspondence with an width of a standard size of, for example, a credit card.

As shown inFIG. 13, in the image reading apparatus1010, an opening1016is formed in a rear portion of a conveying/reading portion1013. At the time of reading of an image on a sheet medium M, the image reading apparatus1010linearly conveys the sheet medium M, and temporarily projects it from the opening1016. This contributes to downsizing of the image reading apparatus1010. For example, in this embodiment, a length D in a depth direction of the image reading apparatus1010is roughly equal to a length D′ in a lengthwise direction of the sheet medium M. A conveying path SW of the sheet medium M includes a straight path which is formed to extend from the discharge port1012through a portion of the conveying path SW of the sheet medium M, and to communicate with the saving portion (a conveying path dedicated to the sheet medium M, and a saving area for switchback conveyance in this embodiment)1032open to the bent portion1031. In this embodiment, for example, this saving portion1032is open, as the opening1016, to the rear portion (rear surface) of the image reading apparatus1010. Note that a conveying method of the sheet medium M will be described in detail in a second conveying method (to be described later).

The image reading apparatus1010can convey a document and read an image by two different conveying methods to be described below.

The operation of the image reading apparatus1010in a first conveying method will be described below with reference toFIG. 15.

In the first conveying method, a document (sheet medium S) is fed from the tray1001, and is discharged outside the apparatus from the discharge portion1006via the conveying path1003. In the first conveying method, the sheet medium S is conveyed by rotating a plurality of first conveying roller pairs1041and1041′ and a plurality of second conveying roller pairs1061and1061′ (seeFIG. 13).

The user places a bundle of sheets as documents on the tray1001. Then, a reading start instruction is accepted from the user via a reading controller (not shown). This reading controller is, for example, an operation unit arranged on the image reading apparatus1010or a computer connected to the image reading apparatus1010via a network.

Upon reception of the reading start instruction, the image reading apparatus1010starts conveyance of a document by the first conveying method. When the conveyance of the document is started, each sheet medium S placed on the tray1001is conveyed inside the apparatus in a first conveying direction in a normal rotation conveyance mode shown inFIG. 15. More specifically, a sheet medium, which is separated one by one from a bundle of sheets by the feed portion1002, is conveyed to the first conveying roller pair1041via the bent portion1031, and is then conveyed to the image reading portion1005by the first conveying roller pair1041. In this case, the detection sensor1009detects an arrival timing of the leading end of the sheet medium S to the image reading portion1005, thereby starting an image reading operation. Upon completion of the image reading operation, the leading end of the sheet medium S pushes up the rib portions1641of the guide unit1064via the second conveying roller pair1061, which is rotated in a normal direction. The guide unit1064, which includes rotary fulcrum portions1642on the upper portion of the conveying path1003, is rotated when it is pushed by the sheet medium S, and is retracted from the conveying path1003. Then, the sheet medium S is sequentially discharged outside the apparatus from the discharge portion1006.

The operation of the image reading apparatus1010in a second conveying method will be described below with reference toFIGS. 16 and 17.

In the second conveying method, a sheet medium M is fed from a gap between the two parallel ribs, which close the conveying path1003, of the guide unit1064in the discharge portion1006. At this time, even when the user obliquely inserts the sheet medium M, the sheet medium M is rotated to have the guide unit1064as a fulcrum, thus correcting any skew, as shown inFIG. 17. That is, the guide unit1064also serves as a correction (reclaim) portion required to regulate a movement in the widthwise direction of the sheet medium M and to prevent any skewed insertion. The sheet medium M, whose skewed insertion is corrected at the time of insertion of the sheet medium M, is conveyed toward the saving portion1032when the respective rollers are rotated in a reverse direction. After that, the sheet medium M is conveyed toward the discharge portion1006again when the respective rollers are rotated in a normal direction, and is discharged from the discharge portion1006. Note that in the second conveying method, for example, a card having a relatively high rigidity is applicable as a document (sheet medium M). Note that the interior of the conveying path1003in the image reading apparatus1010is formed with recessed grooves (concave portions) in correspondence with the thickness of the sheet medium M, so as to commonly convey the sheet medium S and the sheet medium M which is thicker than the sheet medium S. For this reason, the sheet medium M whose skewed insertion is corrected is conveyed along the card conveying path SW (seeFIG. 13) of the conveying path1003by the switchback conveyance without being skewed.

The following description will be given under the assumption that a card is used as the sheet medium M. Note that the present invention is not limited to this, and an arbitrary sheet medium may be selected as a document. In the second conveying method, the sheet medium M is conveyed by rotating only the second conveying roller pair1041′ and second conveying roller pair1061′ (seeFIG. 13) unlike in the first conveying method. That is, only the required roller pairs are driven in correspondence with the width in the widthwise direction of the sheet medium M. However, the present invention is not limited to this, and a plurality of roller pairs may be used even in the second conveying method.

The user inserts a card into a card insertion port regulated by the rib portions1641of the guide unit1064. Since the rib portions1641are disposed to have a gap larger than the card width by about 5 mm, as described above, they can specify an insertion position. When the image reading apparatus1010detects insertion of the card by the discharge sensor1100, it starts conveyance of the document by the second conveying method. The card is conveyed inside the apparatus in a second conveying direction by rotating the respective rollers in a reverse direction in a reverse rotation conveyance mode shown inFIG. 16to be fed to the image reading portion1005. After that, an image on one face of the card is read, and the card is then fed to the first conveying roller pair1041. The leading end of the card fed to the first conveying roller pair1041avoids the bent portion1031, and is fed to the saving portion1032. The saving portion1032is located on a line that couples the discharge portion1006and conveying portion1004, as shown inFIG. 12, and is arranged to avoid the bent portion1031located between the feed portion1002and conveying portion1004. By arranging the saving portion1032, an apparatus conveying path can be prolonged, thus preventing an increase in size of the apparatus.

After that, when the detection sensor1009detects that the trailing end of the card has passed through the image reading portion1005, the first and second conveying roller pairs1041and1061are rotated by the driving portion (not shown) in the normal direction, as shown inFIG. 15, thus changing the conveying direction of the card to normal direction, that is, to a direction of the discharge portion1006. After that, the card is conveyed inside the apparatus in the first conveying direction, and when the card passes through the image reading portion1005again, an image on the other face is read. Then, the card is discharged outside the apparatus from the discharge portion1006. Note that in this embodiment, one driving motor is used as the driving portion to drive the overall apparatus.

The second conveying method in the image reading apparatus1010, which is downsized according to this embodiment, will be described in more detail below with reference toFIGS. 13,14, and17. In the image reading apparatus1010, the discharge port1012includes a card feed port sectioned by the rib portions1641of the guide unit1064, as shown inFIG. 14. Thus, a movement in the widthwise direction is substantially restricted. After that, card side portions of a card are guided by the right and left rib portions1641of the guide unit1064, as shown inFIG. 17. Even when the card is obliquely inserted by mistake, the card side portions contact the guide unit1064. Even when card conveyance in a forward path is started, the card is conveyed along the inner surfaces (rib portions1641) of the guide unit1064from its leading end side to have the guide unit1064as the center (insertion reference), thus effectively preventing any skew (especially, skewed insertion) of the card.

InFIG. 13, in a state in which after the card is inserted into the card feed port, the leading end of the card reaches a rear end portion of the image reading apparatus1010, the entire card is temporarily housed inside the image reading apparatus1010. After that, when the trailing end portion of the card has passed the detection sensor1009, the card goes into the saving portion1032, and the respective rollers are rotated in the reverse direction. At this time, the leading end portion side of the card temporarily projects from the opening1016. In this embodiment, the opening1016is formed in the rear surface side of the image reading apparatus1010, and the end portion of the card temporarily projects from the opening1016at the time of switchback. For example, such opening1016may not formed, and a space that allows the switchback conveyance may be assured inside the apparatus. In some cases, the card may be directly discharged from the opening1016on the rear surface side of the image reading apparatus1010without executing the switchback conveyance.

Note that the image reading apparatus1010includes wall portions (conveying guides of the medium M) on at least portions corresponding to the discharge port1012side and its opposite side (opening1016side) of the conveying/reading portion1013in the card conveying path as regulation wall portions used to prevent any skew of the card, thus correcting skews in both forward and backward paths.

In this way, the image reading apparatus1010of this embodiment attains switchback conveyance (second conveying method) of the sheet medium M (card) by commonly using a portion of the conveying path, while attaining conveyance (first conveying method) of the sheet medium S shown inFIG. 12. Hence, any skew of the sheet medium M can be effectively prevented, and image reading quality can be improved. Also, conveyance errors such as jams upon conveyance of the sheet medium M can be prevented, thus efficiently reading an image on the sheet medium M.

This embodiment has exemplified the case in which the guide unit1064cannot be detached from the image reading apparatus1010. For example, the guide unit1064is detachably configured by dropping the rotary fulcrums1642of the guide unit1064into U-shaped grooves, and the same effects can also be obtained. Operations and the like are the same as the above embodiment, and a description thereof will not be repeated.

This embodiment has exemplified the image reading apparatus1010. However, the present invention is applicable to a media conveying apparatus for a sheet, card, and the like, which includes a predetermined processing unit such as an image forming unit in place of the image reading units1051and1052.

This application claims the benefit of Japanese Patent Applications No. 2010-246736, filed Nov. 2, 2010, and No. 2011-189262, filed Aug. 31, 2011, which are hereby incorporated by reference herein in their entirety.