Image reading apparatus

A feed detection unit which detects a document which is fed is provided at a position between a pinching position at which a feed roller and a frictional force application portion pinch the document and an intersecting position at which a tangential line of the feed roller which is closer to a downstream side in a transport direction than the pinching position is perpendicular to a transport path in the transport direction, which is a different position from the feed roller in a width direction which intersects the transport direction.

BACKGROUND

1. Technical Field

The present invention relates to an image reading apparatus such as a scanner which reads an image of a document.

2. Related Art

In the related art, there is known an image reading apparatus which is provided with a pickup roller (a feed roller) which feeds a document which is placed on a document tray (a placement portion) to a transport path, and a reading unit which reads an image of the document which is fed (JP-A-2015-195442).

In this image reading apparatus, a document detection sensor is provided in the vicinity of the reading unit, and the reading unit is caused to start the reading using the fact that the document detection sensor detects a leading end of a document as a trigger. In the image reading apparatus, the next document is fed using the fact that a rear end of the document is detected by the document detection sensor as a trigger.

In the related art, there is known an image reading apparatus which is provided with a feed roller (a transport roller) which transports a document from the upstream side to the downstream side in the transport direction, and a line sensor (a reading unit) which reads an image of the document which is transported (for example, JP-A-2005-260387).

The image reading apparatus is provided with a pickup roller (a feed roller) which feeds the document which is placed on a paper placement stand (a placement portion) to a transport path, and a separation pad (a frictional force application portion) which separates the documents which are fed by the pickup roller into a single sheet at a time.

Incidentally, since the document detection sensor is provided in the vicinity of the reading unit, for example, in a case in which the next document is fed using the fact that the document detection sensor detects the rear end of the document as a trigger, an interval between the documents is widened and the throughput is decreased.

SUMMARY

An advantage of some aspects of the invention is to provide an image reading apparatus which is capable of improving the throughput.

Binding holes which are referred to as punch holes for binding documents together may be formed in the document. Therefore, in the image reading apparatus, there is a case in which a binding hole is erroneously detected as the rear end of the document, the next document is fed, and the documents are fed in an overlapped state (multi-feed).

Another advantage of some aspects of the invention is to provide an image reading apparatus which is capable of reducing the risk of documents being fed in an overlapped state.

The separation pad separates the document by generating a frictional force which acts in an opposite direction from the transport direction between the document and the separation pad by pushing the document which is fed against the pickup roller.

Therefore, while the document is positioned in a pinching position at which the document is pinched between the pickup roller and the separation pad, a frictional force acts on the document, whereas when the document passes the pinching position, the frictional force of the separation pad no longer acts on the document. Therefore, after the document passes the pinching position, the speed at which the document passes the line sensor increases, and the length of the image which is read by the line sensor is shortened.

Still another advantage of some aspects of the invention is to provide an image reading apparatus which is capable of reducing changes to the length of the image which is read by the reading unit.

Hereinafter, means of the invention and operation effects thereof will be described.

According to an aspect of the invention, there is provided an image reading apparatus which includes a feed unit which includes a feed roller which feeds a document from a placement portion on which the document is placed toward a transport path, and a frictional force application portion which applies a frictional force to an opposite side from a transport direction between the frictional force application portion and the document which is fed by the feed roller, a feed detection unit which detects the document which is fed by the feed unit, and a reading unit which reads an image of the document which is transported along the transport path from an upstream side toward a downstream side in the transport direction, in which the feed detection unit is provided at a position between a pinching position at which the feed roller and the frictional force application portion pinch the document and an intersecting position at which a tangential line of the feed roller which is closer to the downstream side in the transport direction than the pinching position is perpendicular to the transport path in the transport direction, which is a different position from the feed roller in a width direction which intersects the transport direction.

According to this configuration, since the feed detection unit is provided to overlap the feed roller in the transport direction, in comparison with a case in which the feed detection unit is provided closer to the downstream side in the transport direction than the feed roller, it is possible to swiftly detect the document which is fed. Therefore, the interval from when the feeding of the previous document is completed until when the next document is fed is shortened by feeding the document based on the detection results of the feed detection unit, for example, and it is possible to improve throughput.

The image reading apparatus may further include a transport roller which transports the document along the transport direction, in which the feed detection unit may be provided at a position closer to the upstream side in the transport direction than the transport roller.

According to this configuration, since the feed detection unit is provided at a position which is closer to the upstream side in the transport direction than the transport roller, in comparison to a case in which the feed detection unit is provided at a position which is closer to the downstream side in the transport direction than the transport roller, it is possible to narrow the interval between the documents in the transport direction.

The image reading apparatus may further include a multi-feed detection unit which detects multi-feed of the document, in which the feed detection unit may be provided at a position closer to the upstream side in the transport direction than the multi-feed detection unit.

According to this configuration, since the feed detection unit is provided closer to the upstream side in the transport direction than the multi-feed detection unit, in comparison to a case in which the feed detection unit is provided at a position which is closer to the downstream side in the transport direction than the multi-feed detection unit, it is possible to narrow the interval between the documents in the transport direction.

In the image reading apparatus, the multi-feed detection unit may be provided on one side and the feed detection unit is provided on the other side in the width direction to interpose a center of the transport path.

According to this configuration, the feed detection unit is provided on the opposite side from the multi-feed detection unit to interpose the center of the transport path. In other words, since the feed detection unit is provided at a position which is distanced from the multi-feed detection unit in the width direction, it becomes easier to secure the space for providing the feed detection unit.

The image reading apparatus may further include a housing portion which houses the feed roller, in which the feed detection unit may be provided in a different position from the housing portion.

According to this configuration, in a case in which the housing portion is exposed to the outside such as in a case in which the feed roller is exchanged, for example, it is possible to reduce the risk of the feed detection unit being exposed to the outside.

In the image reading apparatus, a drive force transmission unit which transmits a drive force of a drive source to the feed roller may be provided on one side and the feed detection unit is provided on the other side in the width direction to interpose a center of the transport path.

According to this configuration, the feed detection unit is provided on the opposite side from the drive force transmission unit to interpose the center of the transport path. In other words, since the feed detection unit is provided at a position which is distanced from the drive force transmission unit in the width direction, it becomes easier to secure the space for providing the feed detection unit.

In the image reading apparatus, the feed detection unit may be provided at a position which is greater than or equal to 35 mm and less than or equal to 40 mm from a center of the transport path in the width direction.

There is a case in which the holes for passing rings through are formed along the long side in the document of the so-called Bible size. According to this configuration, since the feed detection unit is provided at a position which the holes which are formed in the document of the Bible size pass, it is possible to detect the holes which are formed in the document using the feed detection unit.

According to another aspect of the invention, there is provided an image reading apparatus which includes a feed unit which feeds a document from a placement portion on which the document is placed toward a transport path, a feed detection unit which detects the document which is fed by the feed unit, a transport detection unit which detects the document which is transported along the transport path from an upstream side toward a downstream side in a transport direction, a reading unit which reads an image of the document which is transported, and a control unit which controls driving of the feed unit, in which the feed detection unit and the transport detection unit output a detection signal in which the document is detected and a non-detection signal in which the document is not detected, and in which in a case in which a discharge number which is a number of times the feed detection unit outputs the non-detection signal is less than or equal to one time in a duration from when the feed detection unit outputs the detection signal until when the transport detection unit outputs the detection signal, the control unit drives the feed unit when the feed detection unit outputs the non-detection signal after the transport detection unit outputs the detection signal, and in a case in which the discharge number is greater than or equal to two times, the control unit drives the feed unit when the transport detection unit outputs the non-detection signal.

The plurality of holes are formed in the document to form a row as in refills of a loose leaf file or a notebook, for example. When the holes pass the feed detection unit, the non-detection signal in which the document is not detected is output from a feed detection unit. Therefore, in a case in which the feeding is performed with the row of holes aligned to the transport direction, for example, there is a possibility that the feed detection unit will output the non-detection signal two or more times. In a case in which the row of holes is caused to be perpendicular to the transport direction and the document is fed, the non-detection signal which is output by the feed detection unit is output one or less times. According to this configuration, the control unit controls the driving of the feed unit based on the discharge number of the non-detection signal. In other words, in a case in which the feed detection unit outputs the non-detection signal a plurality of times, and there is a great risk that the holes which are formed in the document will be erroneously detected as the rear end of the document, the control unit drives the feed unit when the transport detection unit outputs the non-detection signal. Therefore, it is possible to reduce the risk of the document being fed in an overlapped state.

In the image reading apparatus, the feed detection unit may be provided in a different position from a center of the transport path in a width direction which intersects the transport direction.

The holes in the document are often formed on the edge of the document. According to this configuration, since the feed detection unit is provided in a different position from the center in the width direction, in comparison to a case in which the feed detection unit is provided in the center in the width direction, it is possible to increase the probability of the feed detection unit detecting the holes of the document.

In the image reading apparatus, the feed detection unit may include a light emitting unit which emits light and a light receiving unit which receives the light which is emitted from the light emitting unit, and the transport detection unit may include a contact portion which comes into contact with the document.

According to this configuration, the feed detection unit which includes the light emitting unit and the light receiving unit, and the transport detection unit which includes the contact portion each detects the document using a different system. Therefore, the detection units of both the feed detection unit and the transport detection unit are capable of reducing the risk of the holes which are formed in the document being erroneously detected as the rear end of the document.

In the image reading apparatus, the feed detection unit and the transport detection unit may be provided in different positions in a width direction which intersects the transport direction.

According to this configuration, the feed detection unit and the transport detection unit are provided in different positions in the width direction. Therefore, in a case in which the row of holes is caused to match the transport direction and the document is fed, and the feed detection unit detects the plurality of holes, the transport detection unit does not detect the holes. Therefore, by feeding the next document based on the detection results of the transport detection unit, it is possible to reduce the risk of the document being fed in an overlapped state.

In the image reading apparatus, the feed detection unit may be provided at a position which is greater than or equal to 35 mm and less than or equal to 40 mm from a center of the transport path in a width direction which intersects the transport direction.

There is a case in which the holes for passing rings through are formed along the long side in the document of the so-called Bible size. According to this configuration, since the feed detection unit is provided at a position which the holes which are formed in the document of the Bible size pass, it is possible to detect the holes which are formed in the document using the feed detection unit.

According to still another aspect of the invention, there is provided an image reading apparatus which includes a feed unit which includes a feed roller which feeds a document from a placement portion on which the document is placed toward a transport path, and a frictional force application portion which applies a frictional force to an opposite side from a feed direction between the frictional force application portion and the document which is fed by the feed roller, a feed detection unit which is provided closer to a downstream side in the feed direction than the frictional force application portion and which detects the document which is fed by the feed unit, a transport roller which transports the document which is fed by the feed unit from an upstream side to a downstream side in a transport direction, a reading unit which reads an image of the document which is transported by the transport roller, and a control unit which controls driving of the transport roller, in which the control unit decelerates a transport speed at which the transport roller transports the document when the feed detection unit detects a rear end of the document.

According to this configuration, since the control unit decelerates the transport speed when the feed detection unit detects the rear end of the document, changes in the speed at which the document passes the reading unit are reduced. Therefore, it is possible to reduce changes in the length of the image which is read by the reading unit.

In the image reading apparatus, the control unit may accelerate the transport speed once the rear end of the document passes the reading unit.

For example, when the previous document is transported at the slow transport speed and the subsequent document is transported at the fast transport speed, the subsequent document may catch up to the previous document. Addressing this point, according to this configuration, since the transport speed is increased once the document passes the reading unit, it is possible to improve throughput while reducing the influence on the image which is read by the reading unit.

The image reading apparatus may further include a transport detection unit which is provided at a position between the feed detection unit and the reading unit in the transport direction, and which detects the document which is transported, and a rotation detection unit which detects a number of rotations of the transport roller, in which the control unit may accelerate the transport speed once the number of rotations which is detected by the rotation detection unit exceeds a predetermined number of times after the transport detection unit detects the rear end of the document.

According to this configuration, it is possible to accurately acquire the position of the document in the transport path based on the detection results of the transport detection unit and the rotation detection unit. Therefore, it is possible to reduce the risk of the transport speed being modified before the document passes the reading units.

The image reading apparatus may further include a discharge roller which discharges the document which is transported by the transport roller, in which the control unit may decelerate a discharge speed at which the discharge roller discharges the document in accordance with decelerating the transport speed.

According to this configuration, since the discharge speed is decelerated in accordance with the decelerating the transport speed, it is possible to reduce the speed difference between the transport speed and the discharge speed. Therefore, it is possible to favorably perform the transferring of the document from the transport roller to the discharge roller and the transporting of the document.

In the image reading apparatus, the transport speed may be faster than a feed speed at which the feed unit feeds the document, and the control unit may accelerate the feed speed when a transport detection unit which detects the document which is transported detects the rear end of the document.

According to this configuration, when the transport detection unit detects the rear end of the document which is previously fed, the control unit accelerates the feed speed. Therefore, it is possible to reduce the speed difference between the feed speed and the transport speed. Therefore, it is possible to smoothly transfer the document which is subsequently fed from the feed unit to the transport roller.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, description will be given of an embodiment of an image reading apparatus with reference to the drawings. The image reading apparatus of the present embodiment is a sheet feed scanner in which a fixed reading unit reads an image of a document which is transported, for example.

First Embodiment

Hereinafter, description will be given of the first embodiment of the image reading apparatus.

As illustrated inFIG. 1, an image reading apparatus11is provided with a main body portion12and a tilting portion14. The main body portion12has a substantially trapezoidal box shape as viewed from the side surface, and the tilting portion14is capable of tilting around a shaft13which is provided on the main body portion12. In other words, the tilting portion14tilts between a closed position which is indicated by a solid line inFIG. 1, and an opened position which is indicated by a double-dot-dash line inFIG. 1.

The image reading apparatus11is provided with a placement portion16, and a feed unit18. It is possible to place a plurality of documents D on the placement portion16in a stacked state, and the feed unit18feeds the document D from the placement portion16toward a transport path17which is indicated by a dot-dash line inFIG. 1. The feed unit18includes a feed roller19and a frictional force application portion20. The feed roller19feeds the document D from the placement portion16toward the transport path17, and the frictional force application portion20applies a frictional force toward the opposite side from a transport direction Y between the frictional force application portion20and the document D which is fed by the feed roller19. The frictional force application portion20of the present embodiment is a separation roller which rotates in a state of being in contact with the documents D to separate the documents D from each other. The feed unit18is provided to be capable of being exchanged by positioning the tilting portion14in the opened position. In other words, the feed roller19is provided to be capable of being attached and detached with respect to the main body portion12, and the frictional force application portion20is provided to be capable of being attached and detached with respect to the tilting portion14.

A transport roller22which transports the document D along the transport direction Y, and a transport follower roller23which rotates to follow the rotation of the transport roller22are provided at a position which is closer to the downstream side in the transport direction Y than the feed unit18so as to interpose the transport path17. A pair of reading units24which read an image of the document D are provided at a position closer to the downstream side in the transport direction Y than the transport roller22so as to extend in a main scanning direction (a width direction X) on both sides, that is, the obverse and the reverse surfaces of the transport path17. At least one of the reading units of the invention may be provided, and the invention is not limited to the present embodiment.

In other words, the transport roller22transports the document D which is fed by the feed unit18from the upstream side toward the downstream side in the transport direction Y. The reading unit24which is provided on the main body portion12reads an image of a first surface (for example, the obverse surface) of the document D which is transported along the transport path17from the upstream side to the downstream side in the transport direction Y. The reading unit24which is provided on the tilting portion14reads an image of a second surface (for example, the reverse surface) of the document D which is transported along the transport path17from the upstream side to the downstream side in the transport direction Y.

A discharge roller25which causes the document D to be discharged from the main body portion12, a discharge driven roller26which rotates to follow the rotation of the discharge roller25, and a discharge portion27to which the document D is discharged are provided closer to the downstream side in the transport direction Y than the reading units24.

The image reading apparatus11is provided with a feed motor28and a transport motor29. The feed motor28is an example of a drive source for rotating the feed roller19, and the transport motor29is a drive source for rotating the transport roller22. The transport motor29is connected to the frictional force application portion20and the discharge roller25, and also rotates the frictional force application portion20and the discharge roller25.

The feed roller19, the transport roller22, and the discharge roller25rotate forward together with the driving of the feed motor28and the transport motor29so as to transport the document D from the upstream side to the downstream side in the transport direction Y. The frictional force application portion20rotates backward together with the driving of the transport motor29so as to apply a frictional force to the document D in the opposite direction from the transport direction Y. The transport roller22and the discharge roller25rotate faster than the feed roller19, and the transport speed of the document D by the transport roller22is faster than the feed speed of the document D by the feed roller19.

The image reading apparatus11is provided with a document detection unit31and a transport detection unit32. The document detection unit31is capable of detecting the document D which is placed on the placement portion16, and the transport detection unit32is capable of detecting the document D which is transported. The transport detection unit32is provided in approximately the same position as the transport roller22in the transport direction Y. Each of the document detection unit31and the transport detection unit32of the present embodiment is a contact sensor which includes a lever, for example, and detects the presence or absence of the document D due to the lever being pushed by the document D.

As illustrated inFIG. 2, a pair of guide portions34which guide both ends in the width direction X of the document D which is placed on the placement portion16are provided on the placement portion16. InFIG. 2, a center position in the width direction X of the placement portion16and the transport path17is indicated using a dot-dash line as a center line L1along the transport direction Y. The pair of guide portions34are provided to be capable of sliding in the width direction X so as to approach each other or separate from each other such that the pair of guide portions34have the same distance from the center line L1in the width direction X as each other. The document detection unit31is provided in the center of the placement portion16in the width direction X, and the transport detection unit32is provided in the center of the transport path17in the width direction X.

A housing portion35which houses the feed roller19is provided at a position between the document detection unit31and the transport detection unit32in the transport direction Y. The feed roller19is housed in the housing portion35in a state of being connected to a drive force transmission unit36which transmits the drive force of the feed motor28to the feed roller19. The housing portion35of the present embodiment is a recessed portion and is covered by a cover37in a state in which the feed roller19is housed in the housing portion35. In other words, the cover37covers the housing portion35in a state in which the feed roller19is exposed, and a portion of the transport path17is formed by the surface of the cover37.

The image reading apparatus11is provided with a feed detection unit38and a multi-feed detection unit39. The feed detection unit38is capable of detecting the document D which is fed by the feed unit18, and the multi-feed detection unit39is capable of detecting multi-feeding of the document D. The feed detection unit38is provided in a different position from the housing portion35, which is a different position from the feed roller19in the width direction X which intersects the transport direction Y. The multi-feed detection unit39is provided on one side and the feed detection unit38is provided on the other side in the width direction X to interpose the center line L1. The feed detection unit38is provided at a position which is closer to the upstream side in the transport direction Y than the multi-feed detection unit39, and is provided at a position which is closer to the upstream side in the transport direction Y than the transport roller22.

The multi-feed detection unit39is provided closer to the drive force transmission unit36side than the center line L1in the width direction X. In other words, the drive force transmission unit36is provided on one side and the feed detection unit38is provided on the other side in the width direction X to interpose the center line L1.

The feed detection unit38is provided at a position in which an interval A from the center line L1in the width direction X is greater than or equal to 35 mm and less than or equal to 40 mm. The interval A is an interval between the center line L1and the middle of a detection region B of the feed detection unit38, and according to the document D of the so-called Bible size, is preferably greater than or equal to 35 mm and less than or equal to 40 mm, and is more preferably greater than or equal to 37 mm and less than or equal to 40 mm.

Next, description will be given of the document D of the Bible size.

As illustrated inFIG. 3, the document D of the Bible size is the document D for exchanging or refilling which is referred to as a refill corresponding to a pocket notebook of a B6 size. The size of the document D is often a rectangular shape with a width W of 95 mm, and a height H of 170 mm to 175 mm. A plurality of (for example, six) holes41may be formed along the long side in the document D. A diameter ϕ of the hole41is often 5 mm to 7 mm, and a dimension W1from the end (the long side) of the document D to the hole41is often 6 mm to 7 mm.

InFIG. 3, a middle line L2of the document D is depicted using a dot-dash line. The middle line L2is a line which is parallel to the long side, and is a line which passes through the middle of the short side. The document D is placed on the placement portion16and is fed and transported so as to align the middle line L2of the document D with the center line L1of the image reading apparatus11.

The diameter ϕ of the hole41and the dimension W1are defined by the format of each of the documents D; however, inFIGS. 4 and 5, documents D which have holes41of different formats are depicted in order to simplify explanation.

In a case in which the diameter ϕ of the holes41is 7 mm as illustrated inFIG. 4, by providing the feed detection unit38at a position at which the interval A with the center line L1is greater than or equal to 35 mm and is less than or equal to 40 mm, at least a portion of the holes41of the document D which is transported overlaps with the feed detection unit38, and it is possible to detect the holes41using the feed detection unit38.

In other words, in a case in which the diameter ϕ is 7 mm, the holes41are positioned in a range of greater than or equal to 33.5 mm and less than or equal to 41.5 mm from the middle line L2. Therefore, by setting the interval A to greater than or equal to 35 mm or less than or equal to 40 mm which is a range closer to the inside than the range in which the holes41of the maximum diameter can be formed by the amount of the radius (1.5 mm in the present embodiment) of the detection region B, it is possible to cause the holes41with the diameter ϕ of 7 mm to overlap the feed detection unit38. In a case in which the diameter ϕ of the holes41is 5 mm, it is possible to cause at least a portion of the holes41to overlap the feed detection unit38.

As illustrated inFIG. 5, the holes41with the diameter ϕ of 5 mm are positioned in a range of greater than or equal to 35.5 mm and less than or equal to 41.5 mm from the middle line L2. Therefore, by setting the interval A to greater than or equal to 37 mm or less than or equal to 40 mm which is a range closer to the inside than the range in which the holes41of the minimum diameter can be formed by the amount of the radius of the detection region B, it is possible improve the detection accuracy of the holes41by the feed detection unit38.

As illustrated inFIG. 6, the feed detection unit38is an optical sensor, and includes a light emitting unit43which emits light, and a light receiving unit44which receives the light which is emitted by the light emitting unit43. The light emitting unit43and the light receiving unit44are disposed in opposing positions to interpose the transport path17. A region which is a region between the light emitting unit43and the light receiving unit44and overlaps the transport path17is the detection region B. In other words, the light emitting unit43emits light toward the detection region B, and the light receiving unit44receives the light which passes through the detection region B. Therefore, when the document D is positioned in the detection region B, the light is blocked by the document D, the light reception amount which is received by the light receiving unit44is reduced, and the feed detection unit38detects the document D.

The feed detection unit38is provided such that the detection region B is positioned at a position in the transport direction Y between a pinching position P1and an intersecting position P2. The pinching position P1is a position at which the feed roller19and the frictional force application portion20pinch the document D. The intersecting position P2is a position closer to the downstream side in the transport direction Y than the pinching position P1at which a tangential line T of the feed roller19intersects the transport path17in a perpendicular manner.

The tangential line T is a common tangential line which is in contact with both the side surface of the cylindrical feed roller19and the side surface of the cylindrical frictional force application portion20. In other words, the feed detection unit38is provided such that the detection region B is positioned closer to the upstream side in the transport direction Y than the intersecting position P2which is also an intersecting point between the common tangential line between the feed roller19and the frictional force application portion20and the transport path17.

The feed roller19and the frictional force application portion20are formed of rubber, sponge, or the like, and may elastically deform, for example. In other words, the feed roller19and the frictional force application portion20may come into surface contact. In this case, a downstream end in the transport direction Y of the surfaces which are contacting each other of the feed roller19and the frictional force application portion20is the pinching position P1, and the feed detection unit38is provided between the pinching position P1and the intersecting position P2. Therefore, the feed detection unit38detects the document D which leaves the feed unit18.

The multi-feed detection unit39is an ultrasonic wave sensor, and a signal transmission unit45which is capable of transmitting an ultrasonic wave, and a signal reception unit46which is capable of receiving the ultrasonic wave which is transmitted by the signal transmission unit45are disposed in opposing positions to interpose the transport path17. The multi-feed detection unit39detects multi-feeding of the document D using the principle that the ultrasonic wave will attenuate in the gap between a plurality of the documents D which are fed overlapped.

Next, description will be given of the electrical configuration of the image reading apparatus11.

As illustrated inFIG. 7, the image reading apparatus11is provided with a control unit48which performs overall control of the driving of the mechanisms in the image reading apparatus11. In other words, the control unit48controls the driving of the reading units24, the feed motor28, and the transport motor29based on the detection results of the document detection unit31, the feed detection unit38, the multi-feed detection unit39, and the transport detection unit32.

Next, with reference to the flowchart illustrated inFIG. 8, description will be given of a feeding method in the image reading apparatus11based on the image reading process routine. The image reading process routine is executed at the timing at which a job of reading an image is started.

As illustrated inFIG. 8, the control unit48drives the feed motor28and the transport motor29in step S101, and causes the feed unit18to feed the document D (a first feeding process). In step S102, the control unit48determines whether or not the document D is multi-fed based on the detection results of the multi-feed detection unit39.

In a case in which the multi-feed detection unit39does not detect multi-feed (step S102: NO), in step S103, the control unit48determines the presence or absence of the holes41in the document D based on the detection results of the feed detection unit38. In a case in which the feed detection unit38does not detect the holes41(step S103: YES), in step S104, the control unit48determines whether or not the transport detection unit32detects the leading end of the document D. In other words, in a case in which the transport detection unit32does not detect the document D (step S104: NO), the control unit48determines that the document D is not transported to the transport detection unit32, and transitions the process to step S102.

When the transport detection unit32detects the document D, the control unit48determines that the leading end of the document D is transported to the transport detection unit32(step S104: YES), and in step S105, executes the no-hole feed process routine.

In step S103, in a case in which the feed detection unit38detects the holes41of the document D (step S103: NO), in step S106, the control unit48executes the hole-present feed process routine.

In the following step S107, the control unit48determines whether or not the rear end of the document D is past the reading units24. In other words, in a case in which a predetermined time is not elapsed from when the transport detection unit32switches from a state of detecting the document D to a state of not detecting the document D, for example, the control unit48determines that the rear end of the document D is yet to pass the reading units24and waits (step S107: NO). In a case in which the predetermined time is elapsed from when the transport detection unit32switches from a state of detecting the document D to a state of not detecting the document D, the control unit48determines that the rear end of the document D is past the reading units24(step S107: YES).

In step S108, the control unit48ends the reading of the image by the reading units24, and in step S109, stops the transport motor29and ends the image reading process routine.

In step S102, when multi-feed is detected by the multi-feed detection unit39(step S102: YES), in step S110, the control unit48stops the feed motor28and transitions the process to step S108.

Next, description will be given of the no-hole feed process routine of step S105(refer toFIG. 8) with reference to the flowchart illustrated inFIG. 9.

As illustrated inFIG. 9, in step S201, the control unit48stops the feed motor28. In step S202, the control unit48causes the reading units24to start the reading of an image.

In step S203, the control unit48determines whether or not the document D is multi-fed based on the detection results of the multi-feed detection unit39. In a case in which the multi-feed detection unit39does not detect multi-feed (step S203: NO), in step S204, the control unit48determines whether or not the feed detection unit38detects the rear end of the document D (a rear end detection process).

In other words, in a case in which the feed detection unit38detects the document D, the control unit48determines that the rear end of the document D is yet to pass the feed detection unit38(step S204: NO), and transitions the process to step S203. When the detection results of the feed detection unit38change from a state in which the document D is detected to a state in which the document D is not detected, the control unit48determines that the rear end of the document D is detected by the feed detection unit38(step S204: YES), and transitions the process to step S205.

In step S205, the control unit48determines whether or not the next document D is placed on the placement portion16based on the detection results of the document detection unit31. In a case in which the document D is placed on the placement portion16(step S205: NO), the control unit48transitions the process to step S101(a second feeding process). In other words, the control unit48causes the next document D to be fed with the rear end of the document D is detected by the feed detection unit38.

In a case in which the next document D is not placed on the placement portion16(step S205: YES), the control unit48ends the no-hole feed process routine and transitions the process to step S107.

In step S203, when multi-feed is detected by the multi-feed detection unit39(step S203: YES), in step S206, the control unit48stops the feed motor28and transitions the process to step S108.

Next, description will be given of the hole-present feed process routine of step S106(refer toFIG. 8) with reference to the flowchart illustrated inFIG. 10.

As illustrated inFIG. 10, in step S301, the control unit48determines whether or not the document D is multi-fed based on the detection results of the multi-feed detection unit39.

In a case in which the multi-feed detection unit39does not detect multi-feed (step S301: NO), in step S302, the control unit48determines whether or not the transport detection unit32detects the leading end of the document D, and in a case in which the transport detection unit32does not detect the document D (step S302: NO), the control unit48transitions the process to step S301.

When the transport detection unit32detects the document D, the control unit48determines that the leading end of the document D is transported to the transport detection unit32(step S302: YES), and in step S303, stops the feed motor28. In step S304, the control unit48causes the reading units24to start the reading of an image.

In step S305, the control unit48determines whether or not the document D is multi-fed based on the detection results of the multi-feed detection unit39. In a case in which the multi-feed detection unit39does not detect multi-feed (step S305: NO), in step S306, the control unit48determines whether or not the transport detection unit32detects the rear end of the document D.

In other words, in a case in which the transport detection unit32detects the document D, the control unit48determines that the rear end of the document D is yet to pass the transport detection unit32(step S306: NO), and transitions the process to step S305. When the detection results of the transport detection unit32change from a state in which the document D is detected to a state in which the document D is not detected, the control unit48determines that the rear end of the document D is detected by the transport detection unit32(step S306: YES), and transitions the process to step S307.

In step S307, the control unit48determines whether or not the next document D is placed on the placement portion16based on the detection results of the document detection unit31. In a case in which the document D is placed on the placement portion16(step S307: NO), the control unit48transitions the process to step S101. In a case in which the document D is not placed on the placement portion16(step S307: YES), the control unit48ends the hole-present feed process routine.

In step S301and step S305, when multi-feed is detected by the multi-feed detection unit39(step S301, step S305: YES), in step S308, the control unit48stops the feed motor28and transitions the process to step S108.

Next, description will be given of the operations of the image reading apparatus11.

When a job is input to the image reading apparatus11, the control unit48drives the feed motor28and the transport motor29, and feeds and transports the document D.

When the transport detection unit32detects the leading end of the document D, the control unit48stops the feed motor28. In other words, when the transport motor29is driven, the transport roller22rotates to transport the document D, and the feed roller19rotates to follow the document D which is transported by the transport roller22. Meanwhile, the frictional force application portion20rotates backward and continues to apply a frictional force to the document D. The reading units24read an image of the document D at the timing at which the document D passes.

The control unit48modifies the timing at which to feed the next document D according to whether or not the feed detection unit38detects the holes41in the document D in the time from when the feed detection unit38detects the leading end of the document D until when the transport detection unit32detects the leading end of the document D. In other words, in a case in which the feed detection unit38does not detect the holes41, the control unit48drives the feed motor28using the fact that the feed detection unit38detects the rear end of the document D as a trigger. In a case in which the feed detection unit38detects the holes41, the control unit48drives the feed motor28using the fact that the transport detection unit32detects the rear end of the document D as a trigger.

According to the embodiment described above, it is possible to obtain the following effects.

(1) Since the feed detection unit38is provided to overlap the feed roller19in the transport direction Y, in comparison with a case in which the feed detection unit38is provided closer to the downstream side in the transport direction Y than the feed roller19, it is possible to swiftly detect the document D which is fed. Therefore, the interval from when the feeding of the previous document D is completed until when the next document D is fed is shortened by feeding the document D based on the detection results of the feed detection unit38, for example, and it is possible to improve throughput.

(2) Since the feed detection unit38is provided at a position which is closer to the upstream side in the transport direction Y than the transport roller22, in comparison to a case in which the feed detection unit38is provided at a position which is closer to the downstream side in the transport direction Y than the transport roller22, it is possible to narrow the interval between the documents D in the transport direction Y.

(3) Since the feed detection unit38is provided closer to the upstream side in the transport direction Y than the multi-feed detection unit39, in comparison to a case in which the feed detection unit38is provided at a position which is closer to the downstream side in the transport direction Y than the multi-feed detection unit39, it is possible to narrow the interval between the documents D in the transport direction Y.

(4) The feed detection unit38is provided on the opposite side from the multi-feed detection unit39to interpose the center of the transport path17. In other words, since the feed detection unit38is provided at a position which is distanced from the multi-feed detection unit39in the width direction X, it becomes easier to secure the space for providing the feed detection unit38.

(5) Since the feed detection unit38is provided in a different position from the housing portion35, in a case in which the housing portion35is exposed to the outside such as in a case in which the feed roller19is exchanged, for example, it is possible to reduce the risk of the feed detection unit38being exposed to the outside.

(6) The feed detection unit38is provided on the opposite side from the drive force transmission unit36to interpose the center of the transport path17. In other words, since the feed detection unit38is provided at a position which is distanced from the drive force transmission unit36in the width direction X, it becomes easier to secure the space for providing the feed detection unit38.

(7) There is a case in which the holes41for passing rings through are formed along the long side in the document D of the so-called Bible size. Since the feed detection unit38is provided at a position which the holes41which are formed in the document D of the Bible size pass, it is possible to detect the holes41which are formed in the document D using the feed detection unit38.

The first embodiment which is described above can also be modified as described below.

In the embodiment which is described above, the image reading apparatus11may feed a carrier sheet interposing the document D and read an image of the document D. A carrier sheet is formed by one end of two transparent sheets being bonded together, and is used in a case in which the document D of a non-standard size is folded in two and read, or the like. Incidentally, since the carrier sheet is a transparent sheet, in a case in which an optical sensor is used for the feed detection unit38, it is not possible to detect the rear end of the carrier sheet using the feed detection unit38. Therefore, in a case in which an image of the document D is read while using the carrier sheet, in a case in which the transport detection unit32detects the rear end of the carrier sheet, the feed unit18may be caused to feed the next document D. Whether the reading target is the document D or is the document D interposed in the carrier sheet may be input from an input unit (not illustrated) by a user. A detection target portion may be provided on the carrier sheet, and the feed detection unit38may be caused to detect the detection target portion of the carrier sheet.

In the embodiment which is described above, in a case in which the width W of the document D is smaller than double the size of the interval A between the center line L1and the feed detection unit38, the feed unit18may be caused to feed the next document D in a case in which the transport detection unit32detects the rear end of the document D. In other words, in a case in which the transport detection unit32detects the document D whereas the feed detection unit38is yet to detect the document D, the control unit48may perform execution from step S303of the hole-present feed process routine which is illustrated inFIG. 10.

In the embodiment which is described above, in a case in which the feed detection unit38detects the holes41, the control unit48may execute a process which is set according to the document D of the Bible size. It is possible to set this process arbitrarily, using a joining process in which the images of the obverse surface and the reverse surface of the document D which are read by the pair of reading units24are joined, a process in which character information is acquired, or the like.

In the embodiment which is described above, in a case in which the feed detection unit38detects one of the holes41of the document D in the time from when the feed detection unit38detects the leading end of the document D until when the transport detection unit32detects the leading end of the document D, the control unit48may feed the next document D using the fact that the feed detection unit38detects the rear end of the document D as a trigger. In other words, in a case in which the feed detection unit38detects a plurality of the holes41, the next document D may be fed using the fact that the transport detection unit32detects the rear end of the document D as a trigger.

In the embodiment which is described above, the document detection unit31, the transport detection unit32, the feed detection unit38, and the multi-feed detection unit39may be arbitrary detection units such as those which use contact and those which do not. For example, the feed detection unit38may be a contact sensor which includes a lever. For example, the feed detection unit38may be an image sensor, and may detect the document D using image processing.

In the embodiment which is described above, a configuration may be adopted in which the discharge roller25and the discharge driven roller26are not provided.

In the embodiment which is described above, the feed detection unit38may be provided at a position which is less than 35 mm from the center line L1in the width direction X. The feed detection unit38may be provided at a position which is distanced from the center line L1in the width direction X by more than 40 mm.

In the embodiment which is described above, the feed detection unit38may be provided closer to the drive force transmission unit36than the center line L1. The drive force transmission unit36may be provided closer to the feed detection unit38side than the center line L1.

In the embodiment which is described above, the image reading apparatus11may be configured to not include the feed motor28. For example, the transport motor29may be connected to the drive force transmission unit36, and whether or not to transmit the drive force of the transport motor29to the feed roller19may be switched using the drive force transmission unit36.

In the embodiment which is described above, the feed detection unit38may be provided inside the housing portion35together with the feed roller19.

In the embodiment which is described above, the image reading apparatus11may be configured to not include the housing portion35.

In the embodiment which is described above, the feed detection unit38may be provided closer to the multi-feed detection unit39side than the center line L1. The multi-feed detection unit39may be provided closer to the feed detection unit38side than the center line L1.

In the embodiment which is described above, a configuration may be adopted in which the transport roller22is not provided. In other words, after the document D which is fed by the feed unit18is transported to the discharge roller25by the feed roller19, the document D may be transported and discharged by the discharge roller25.

In the embodiment which is described above, the feed detection unit38may be provided in a center position of the width direction X in the transport path17. In other words, the feed detection unit38may be provided on the center line L1. In a case in which a plurality of the feed rollers19are provided in the width direction X, the feed detection unit38may be provided at a position between the feed rollers19in the width direction X.

In the embodiment which is described above, the frictional force application portion20may be a separation pad pinches the documents D together with the feed roller19to separate the documents D.

In the embodiment which is described above, the image reading apparatus11is not limited to a sheet feeding type, and may be a flatbed type image reading apparatus which is provided with an automatic document feeding apparatus (an auto sheet feeder) which automatically feeds the documents D. The image reading apparatus11may be applied to a multifunctional device which is configured to be integral with the printing apparatus, a FAX which is provided with a communication function, or the like.

Second Embodiment

Hereinafter, description will be given of a second embodiment of the image reading apparatus.

As illustrated inFIG. 11, an image reading apparatus111is provided with a main body portion112and a tilting portion114. The main body portion112has a substantially trapezoidal box shape as viewed from the side surface, and the tilting portion114is capable of tilting around a shaft113which is provided on the main body portion112. In other words, the tilting portion114tilts between a closed position which is indicated by a solid line inFIG. 11, and an opened position which is indicated by a double-dot-dash line inFIG. 11.

The image reading apparatus111is provided with a placement portion116, and a feed unit118. It is possible to place a plurality of documents D on the placement portion116in a stacked state, and the feed unit118feeds the document D from the placement portion116toward a transport path117which is indicated by a dot-dash line inFIG. 11. The feed unit118includes a feed roller119and a frictional force application portion120. The feed roller119feeds the document D, and the frictional force application portion120causes a frictional force to be generated between the frictional force application portion120and the document D which is fed by the feed roller119. The frictional force application portion120of the present embodiment is a separation roller which rotates in a state of being in contact with the documents D to separate the documents D from each other.

A transport unit121which transports the document D which is fed by the feed unit118from the upstream side to the downstream side in the transport direction Y is provided at a position which is closer to the downstream side in the transport direction Y than the feed unit118. The transport unit121includes a transport roller122which transports the document D, and a transport follower roller123which rotates to follow the rotation of the transport roller122. The transport roller122and the transport follower roller123are provided to interpose the transport path117.

A pair of reading units124which read an image of the document D which is transported are provided at a position closer to the downstream side in the transport direction Y than the transport unit121so as to extend in the main scanning direction (the width direction X) on both sides, that is, the obverse and the reverse surfaces of the transport path117. At least one of the reading units of the invention may be provided, and the invention is not limited to the present embodiment.

In other words, the reading unit124which is provided on the main body portion112reads an image of the first surface (for example, the obverse surface) of the document D which is transported along the transport path117from the upstream side toward the downstream side in the transport direction Y. The reading unit124which is provided on the tilting portion114reads an image of the second surface (for example, the reverse surface) of the document D which is transported along the transport path117from the upstream side to the downstream side in the transport direction Y.

A discharge roller125which causes the document D to be discharged from the main body portion112, a discharge driven roller126which rotates to follow the rotation of the discharge roller125, and a discharge portion127to which the document D is discharged are provided closer to the downstream side in the transport direction Y than the reading units124.

The image reading apparatus111is provided with a feed motor128and a transport motor129. The feed motor128is a drive source for rotating the feed roller119, and the transport motor129is a drive source for rotating the transport roller122. The transport motor129is connected to the frictional force application portion120and a discharge roller125, and also rotates the frictional force application portion120and the discharge roller125. The feed roller119, the transport roller122, and the discharge roller125rotate forward together with the driving of the feed motor128and the transport motor129so as to transport the document D from the upstream side to the downstream side in the transport direction Y. The frictional force application portion120rotates backward together with the driving of the transport motor129so as to apply a frictional force to the document D in the opposite direction from the transport direction Y.

The image reading apparatus111is provided with a placement detection unit131and the feed detection unit132. The placement detection unit131is capable of detecting the document D which is placed on the placement portion116, and the feed detection unit132is capable of detecting the document D which is fed by the feed unit118. The image reading apparatus111is further provided with a transport detection unit133, and a control unit135. The transport detection unit133is capable of detecting the document D which is transported along the transport path117from the upstream side toward the downstream side in the transport direction Y, and the control unit135performs overall control of the driving of the mechanisms in the image reading apparatus111such as the feed unit118.

The feed detection unit132is an optical sensor which includes a light emitting unit137which emits light, and a light receiving unit138which receives the light which is emitted from the light emitting unit137. The light emitting unit137and the light receiving unit138are disposed in opposing positions to interpose the transport path117.

The transport detection unit133is provided at a position which is closer to the downstream side in the transport direction Y than the feed detection unit132, which is substantially the same position as the transport roller122in the transport direction Y. The placement detection unit131and the transport detection unit133are contact sensors which include contact portions31aand33asuch as levers, for example, which come into contact with the document D, and detect the presence or absence of the document D due to the contact portions31aand33abeing pushed and displaced by the document D.

As illustrated inFIG. 12, a pair of guide portions140which guide both ends in the width direction X which intersects the transport direction Y of the document D which is placed on the placement portion116are provided on the placement portion116. InFIG. 12, a center position in the width direction X of the placement portion116and the transport path117is indicated using a dot-dash line as the center line L1along the transport direction Y. The pair of guide portions140are provided to be capable of sliding in the width direction X so as to approach each other or separate from each other such that the pair of guide portions140have the same distance from the center line L1in the width direction X as each other. The placement detection unit131is provided in the center of the placement portion116in the width direction X, and the transport detection unit133is provided in the center of the transport path117in the width direction X.

The feed detection unit132is provided in a different position from the center of the transport path117in the width direction X. In other words, the feed detection unit132and the transport detection unit133are provided in different positions in the width direction X. Specifically, the feed detection unit132is provided at a position in which the interval A from the center line L1in the width direction X is greater than or equal to 35 mm and less than or equal to 40 mm.

The interval A is an interval between the center line L1and the middle of the detection region B of the feed detection unit132, and according to the document D of the so-called Bible size, is preferably greater than or equal to 35 mm and less than or equal to 40 mm, and is more preferably greater than or equal to 37 mm and less than or equal to 40 mm.

The detection region B is a region above the transport path117, the light emitting unit137emits light toward the detection region B, and the light receiving unit138receives the light which passes through the detection region B.

Next, description will be given of the document D of the Bible size. The document D of the Bible size of the present embodiment is the same as in the first embodiment, and thus description thereof will be omitted.

As illustrated inFIG. 3, the document D is placed on the placement portion116and is fed and transported so as to align the middle line L2of the document D with the center line L1of the image reading apparatus111or so as to cause the middle line L2to be substantially perpendicular to the center line L1. In a case in which the middle line L2is caused to be substantially perpendicular to the center line L1, the document D is placed such that the holes41are positioned closer to the downstream side in the transport direction Y than the middle line L2, and is transported.

In a case in which the diameter ϕ of the holes41is 7 mm as illustrated inFIG. 4, by providing the feed detection unit132at a position at which the interval A with the center line L1is greater than or equal to 35 mm and is less than or equal to 40 mm, at least a portion of the holes41of the document D which is transported overlaps with the feed detection unit132, and it is possible to detect the holes41using the feed detection unit132.

In other words, in a case in which the diameter ϕ is 7 mm, the holes41are positioned in a range of greater than or equal to 33.5 mm and less than or equal to 41.5 mm from the middle line L2. Therefore, by setting the interval A to greater than or equal to 35 mm or less than or equal to 40 mm which is a range closer to the inside than the range in which the holes41of the maximum diameter can be formed by the amount of the radius (1.5 mm in the present embodiment) of the detection region B, it is possible to cause the holes41with the diameter ϕ of 7 mm to overlap the feed detection unit132.

In a case in which the diameter ϕ of the holes41is 5 mm, it is possible to cause at least a portion of the holes41to overlap the feed detection unit132.

As illustrated inFIG. 5, the holes41with the diameter ϕ of 5 mm are positioned in a range of greater than or equal to 35.5 mm and less than or equal to 41.5 mm from the middle line L2. Therefore, by setting the interval A to greater than or equal to 37 mm or less than or equal to 40 mm which is a range closer to the inside than the range in which the holes41of the minimum diameter can be formed by the amount of the radius of the detection region B, it is possible improve the detection accuracy of the holes41by the feed detection unit132.

Next, description will be given of the electrical configuration of the image reading apparatus111.

As illustrated inFIG. 13, the control unit135controls the driving of the reading units124, the feed motor128, and the transport motor129based on the detection results of the placement detection unit131, the feed detection unit132, and the transport detection unit133.

Next, description will be given of the detection method in which the feed detection unit132and the transport detection unit133detect the document D.

As illustrated inFIG. 14, the feed detection unit132detects the presence or absence of the document D according to the light reception amount which is received by the light receiving unit138, and outputs a detection signal S1in which the document D is detected and a non-detection signal S2in which the document D is not detected. Specifically, in a case in which the light reception amount is greater than a threshold T, the feed detection unit132outputs the non-detection signal S2, and in a case in which the light is blocked by the document D and the light reception amount is less than the threshold T, the feed detection unit132outputs the detection signal S1.

The transport detection unit133detects the presence or absence of the document D according to the displacement of the contact portion31a, and outputs the detection signal S1in which the document D is detected and the non-detection signal S2in which the document D is not detected in the same manner as the feed detection unit132.

Therefore, the feed detection unit132and the transport detection unit133output the non-detection signal S2before the document D is fed, and the signal to be output switches to the detection signal S1at the timing at which the leading end of the document D pass through. The feed detection unit132and the transport detection unit133temporarily output the non-detection signal S2at the timing at which the holes41pass through.

Next, with reference to the flowcharts illustrated inFIGS. 15A and 15B, description will be given of a feeding method in the image reading apparatus111based on the image reading process routine. The image reading process routine is executed at the timing at which a job of reading an image is started.

As illustrated inFIGS. 15A and 15B, the control unit135drives the feed motor128and the transport motor129in step S401, and causes the feed unit118to feed the document D (the first feeding process). In step S402, the control unit135determines whether or not the feed detection unit132detects the leading end of the document D. In other words, in a case in which the non-detection signal S2is output from the feed detection unit132and the feed detection unit132does not detect the document D (step S402: NO), the control unit135determines that the document D is yet to be fed to the feed detection unit132, and waits until the document D is fed.

When the control unit135acquires the detection signal S1which is output from the feed detection unit132(a feed signal acquisition process), the control unit135determines that the leading end of the document D is transported to the feed detection unit132(step S402: YES), and transitions the process to step S403.

In step S403, the control unit135determines whether or not the feed detection unit132detects the holes41which are formed in the document D. In other words, when the signal which is output from the feed detection unit132switches from the detection signal S1to the non-detection signal S2, the control unit135determines that the holes41are detected (step S403: YES), in step S404, increments a discharge number which is the number of times the non-detection signal S2is output, and transitions the process to step S405.

In a case in which the non-detection signal S2is not output from the feed detection unit132, the control unit135determines that the holes41are not detected (step S403: NO), and transitions the process to step S405.

In step S405, the control unit135determines whether or not the transport detection unit133detects the leading end of the document D.

In other words, in a case in which the non-detection signal S2is output from the transport detection unit133and the transport detection unit133does not detect the document D (step S405: NO), the control unit135determines that the document D is not transported to the transport detection unit133, and transitions the process to step S403. When the control unit135acquires the detection signal S1which is output from the transport detection unit133(a transport signal acquisition process), the control unit135determines that the leading end of the document D is transported to the transport detection unit133(step S405: YES).

In step S406, the control unit135causes the feed motor128to stop, and further, in step S407, causes the reading units124to start the reading of an image. In the following step S408, the control unit135determines whether or not the discharge number which is incremented in step S404is greater than or equal to two times.

The discharge number is the number of times that the non-detection signal S2is output from the feed detection unit132during the time from when the detection signal S1which is output from the feed detection unit132in step S402is acquired until when the detection signal S1which is output from the transport detection unit133in step S405is acquired.

In a case in which the discharge number is less than or equal to one time (step S408: NO), the control unit135transitions the process to step S409. In a case in which the discharge number is greater than or equal to two times (step S408: YES), the control unit135transitions the process to step S410.

In step S409, the control unit135determines whether or not the feed detection unit132detects the rear end of the document D. In other words, in a case in which the detection signal S1is output from the feed detection unit132and the feed detection unit132detects the document D, the control unit135determines that the document D is yet to pass the feed detection unit132, and waits (step S409: NO). When the non-detection signal S2is output from the feed detection unit132, the control unit135determines that the feed detection unit132detects the rear end of the document D (step S409: YES), and transitions the process to step S411.

In step S410, the control unit135determines whether or not the transport detection unit133detects the rear end of the document D. In other words, in a case in which the detection signal S1is output from the transport detection unit133and the transport detection unit133detects the document D, the control unit135determines that the document D is yet to pass the transport detection unit133, and waits (step S410: NO). When the non-detection signal S2is output from the transport detection unit133, the control unit135determines that the transport detection unit133detects the rear end of the document D (step S410: YES), and transitions the process to step S411.

In step S411, the control unit135determines whether or not the next document D is placed on the placement portion116based on the detection results of the placement detection unit131. In a case in which the document D is placed on the placement portion116(step S411: NO), the control unit135transitions the process to step S401and feeds the next document D using the feed unit118(the second feeding process).

In other words, in a case in which the discharge number is less than or equal to one time in step S408, when the non-detection signal S2is output from the feed detection unit132after the detection signal S1is output from the transport detection unit133in step S405, the control unit135causes the next document D to be fed in step S401. In a case in which the discharge number is greater than or equal to two times in step S408, when the non-detection signal S2is output from the transport detection unit133, the control unit135causes the next document D to be fed in step S401.

In a case in which the next document D is not placed on the placement portion116(step S411: YES), in step S412, the control unit135determines whether or not the rear end of the document D is past the reading units124. In other words, in a case in which a predetermined time is not elapsed from when the transport detection unit133outputs the non-detection signal S2, for example, the control unit135determines that the rear end of the document D is yet to pass the reading units124and waits (step S412: NO). In a case in which the predetermined time is elapsed from when the transport detection unit133outputs the non-detection signal S2, the control unit135determines that the rear end of the document D is past the reading units124(step S412: YES).

In step S413, the control unit135ends the reading of the image by the reading units124, and in step S414, stops the transport motor129and ends the image reading process routine.

Next, description will be given of the operations of the image reading apparatus111.

When a job is input to the image reading apparatus111, the control unit135drives the feed motor128and the transport motor129, and feeds and transports the document D.

When the transport detection unit133detects the leading end of the document D, the control unit135stops the feed motor128. In other words, since the transport motor129is being driven, the transport roller122rotates to transport the document D, and the feed roller119rotates to follow the document D which is transported by the transport roller122. Meanwhile, the frictional force application portion120rotates backward and continues to apply a frictional force to the document D. The reading units124read an image of the document D at the timing at which the document D passes.

The control unit135controls the driving of the feed unit118according to the number of the holes41which are detected by the feed detection unit132in the time from when the feed detection unit132detects the leading end of the document D until when the transport detection unit133detects the leading end of the document D. In other words, the control unit135controls the driving of the feed unit118based on the discharge number which is the number of times the feed detection unit132outputs the non-detection signal S2in the time from when the feed detection unit132outputs the detection signal S1until when the transport detection unit133outputs the detection signal S1.

In other words, in a case in which the document D is transported in a state in which the middle line L2of the document D is substantially perpendicular to the center line L1of the image reading apparatus111, or in a case in which the document D in which the holes41are not formed is transported, the discharge number of the non-detection signal S2becomes less than or equal to one. In this case, the control unit135drives the feed motor128using the fact that the feed detection unit132detects the rear end of the document D as a trigger. In other words, the control unit135drives the feed unit118when the feed detection unit132outputs the non-detection signal S2after the transport detection unit133outputs the detection signal S1.

In a case in which the document D of the Bible size is aligned such that the center line L1matches the middle line L2, the discharge number of the non-detection signal S2is greater or equal to two times. In this case, the control unit135drives the feed motor128using the fact that the transport detection unit133detects the rear end of the document D as a trigger. In other words, the control unit135drives the feed unit118when the transport detection unit133outputs the non-detection signal S2.

According to the embodiment described above, it is possible to obtain the following effects.

(1) The plurality of holes41are formed in the document D to form a row as in refills of a loose leaf file or a notebook, for example. When the holes41pass the feed detection unit132, the non-detection signal S2in which the document D is not detected is output from the feed detection unit132. Therefore, in a case in which the feeding is performed with the row of the holes41aligned to the transport direction Y, for example, there is a possibility that the feed detection unit132will output the non-detection signal S2two or more times. In a case in which the row of the holes41is caused to be perpendicular to the transport direction Y and the document D is fed, the non-detection signal S2which is output by the feed detection unit132is output one or less times. The control unit135controls the driving of the feed unit118based on the discharge number of the non-detection signal S2. In other words, in a case in which the feed detection unit132outputs the non-detection signal S2a plurality of times, and there is a great risk that the holes41which are formed in the document D will be erroneously detected as the rear end of the document D, the control unit135drives the feed unit118when the transport detection unit133outputs the non-detection signal S2. Therefore, it is possible to reduce the risk of the document D being fed in an overlapped state.

(2) The holes41in the document D are often formed on the edge of the document D. Since the feed detection unit132is provided at a different position from the center in the width direction X, in comparison to a case in which the feed detection unit132is provided in the center in the width direction X, it is possible to increase the probability of the feed detection unit132detecting the holes41of the document D.

(3) The feed detection unit132which includes the light emitting unit137and the light receiving unit138, and the transport detection unit133which includes the contact portion31aeach detects the document D using a different system. Therefore, the detection units of both the feed detection unit132and the transport detection unit133are capable of reducing the risk of the holes41which are formed in the document D being erroneously detected as the rear end of the document D.

(4) The feed detection unit132and the transport detection unit133are provided in different positions in the width direction X. Therefore, in a case in which the row of the holes41is caused to match the transport direction Y and the document D is fed, and the feed detection unit132detects the plurality of holes41, the transport detection unit133does not detect the holes41. Therefore, by feeding the next document D based on the detection results of the transport detection unit133, it is possible to reduce the risk of the document D being fed in an overlapped state.

(5) There is a case in which the holes41for passing rings through are formed along the long side in the document D of the so-called Bible size. Since the feed detection unit132is provided at a position which the holes41which are formed in the document D of the Bible size pass, it is possible to detect the holes41which are formed in the document D using the feed detection unit132.

(6) In a case in which the discharge number which is the number of times the feed detection unit132outputs the non-detection signal S2is less than or equal to one time, and it is unlikely that the holes41in the document D will be erroneously detected as the rear end of the document D, the control unit135drives the feed unit118when the feed detection unit132outputs the non-detection signal S2. In other words, since it is possible to shorten the interval from when the feeding of the previous document D is completed until when the feeding of the next document D is started, it is possible to improve the throughput.

Furthermore, the embodiment described above may also be modified as described below.

In the embodiment which is described above, the image reading apparatus111may feed a carrier sheet interposing the document D and read an image of the document D. A carrier sheet is formed by one end of two transparent sheets being bonded together, and is used in a case in which the document D of a non-standard size is folded in two and read, or the like. Incidentally, since the carrier sheet is a transparent sheet, in a case in which an optical sensor is used for the feed detection unit132, it is not possible to detect the rear end of the carrier sheet using the feed detection unit132. Therefore, in a case in which an image of the document D is read while using the carrier sheet, in a case in which the transport detection unit133detects the rear end of the carrier sheet, the feed unit118may be caused to feed the next document D. Whether the reading target is the document D or is the document D interposed in the carrier sheet may be input from an input unit (not illustrated) by a user. A detection target portion may be provided on the carrier sheet, and the feed detection unit132may be caused to detect the detection target portion of the carrier sheet.

In the embodiment which is described above, the frictional force application portion120may be a separation pad pinches the documents D together with the feed roller119to separate the documents D.

In the embodiment which is described above, in a case in which the width W of the document D is smaller than double the size of the interval A between the center line L1and the feed detection unit132, the feed unit118may be caused to feed the next document D when the transport detection unit133detects the rear end of the document D.

In the embodiment which is described above, in a case in which the discharge number is greater than or equal to two, the control unit135may execute a process which is set according to the document D of the Bible size. It is possible to set this process arbitrarily, using a joining process in which the images of the obverse surface and the reverse surface of the document D which are read by the pair of reading units124are joined, a process in which character information is acquired, or the like.

In the embodiment which is described above, the placement detection unit131, the transport detection unit133, and the feed detection unit132may be arbitrary detection units such as those which use contact and those which do not. For example, the feed detection unit132may be a contact sensor which includes a lever. For example, the transport detection unit133may be an optical sensor. The feed detection unit132and the transport detection unit133may be image sensors which detect the document D using image processing, or ultrasonic wave sensors which detect the document D according to the degree of attenuation of an ultrasonic wave.

In the embodiment which is described above, a configuration may be adopted in which the discharge roller125and the discharge driven roller126are not provided.

In the embodiment which is described above, a configuration may be adopted in which the transport unit121is not provided. In other words, after the document D which is fed by the feed unit118is transported to the discharge roller125by the feed roller119, the document D may be transported and discharged by the discharge roller125.

In the embodiment which is described above, the feed detection unit132may be provided at a position which is less than 35 mm from the center line L1in the width direction X. The feed detection unit132may be provided at a position which is distanced from the center line L1in the width direction X by more than 40 mm.

In the embodiment which is described above, the feed detection unit132and the transport detection unit133may be provided in the same position in the width direction X. The feed detection unit132may be provided in a center position of the width direction X in the transport path117.

In the embodiment which is described above, the image reading apparatus111is not limited to a sheet feeding type, and may be a flatbed type image reading apparatus which is provided with an automatic document feeding apparatus (an auto sheet feeder) which automatically feeds the documents D. The image reading apparatus111may be applied to a multifunctional device which is configured to be integral with the printing apparatus, a FAX which is provided with a communication function, or the like.

Third Embodiment

Hereinafter, description will be given of the third embodiment of the image reading apparatus.

As illustrated inFIG. 16, an image reading apparatus211is provided with a main body portion212and a tilting portion214. The main body portion212has a substantially trapezoidal box shape as viewed from the side surface, and the tilting portion214is capable of tilting around a shaft213which is provided on the main body portion212. In other words, the tilting portion214tilts between a closed position which is indicated by a solid line inFIG. 16, and an opened position which is indicated by a double-dot-dash line inFIG. 16.

The image reading apparatus211is provided with a placement portion216, and a feed unit218. It is possible to place a plurality of documents D on the placement portion216in a stacked state, and the feed unit218feeds the document D from the placement portion216toward a transport path217which is indicated by a dot-dash line inFIG. 16. The feed unit218includes a feed roller219and a frictional force application portion220and feeds the document D in a feed direction Y1. The feed roller219feeds the document D, and the frictional force application portion220causes a frictional force to be generated between the frictional force application portion220and the document D which is fed by the feed roller219. The frictional force application portion220of the present embodiment is a separation roller which rotates in a state of being in contact with the documents D to separate the documents D from each other.

A transport unit221which transports the document D which is fed by the feed unit218from the upstream side to the downstream side in a transport direction Y2is provided at a position which is closer to the downstream side in the transport direction Y2than the frictional force application portion220. The feed direction Y1and the transport direction Y2of the present embodiment are substantially the same direction. The transport unit221includes a transport roller222which transports the document D, and a transport follower roller223which rotates to follow the rotation of the transport roller222. The transport roller222and the transport follower roller223are provided to interpose the transport path217.

A pair of reading units224which read an image of the document D which is transported by the transport roller222are provided at a position closer to the downstream side in the transport direction Y2than the transport roller222so as to extend in the main scanning direction (the width direction X) on both sides, that is, the obverse and the reverse surfaces of the transport path217. At least one of the reading units of the invention may be provided, and the invention is not limited to the present embodiment.

In other words, the reading unit224which is provided on the main body portion212reads an image of the first surface (for example, the obverse surface) of the document D which is transported along the transport path217from the upstream side toward the downstream side in the transport direction Y2. The reading unit224which is provided on the tilting portion214reads an image of a second surface (for example, the reverse surface) of the document D which is transported along the transport path217from the upstream side toward the downstream side in the transport direction Y2.

A discharge roller225which discharges the document D which is transported using the transport roller222, a discharge driven roller226which rotates to follow the rotation of the discharge roller225, and a discharge portion227to which the document D is discharged are provided closer to the downstream side in the transport direction Y2than the reading units224.

The image reading apparatus211is provided with a feed motor228and a transport motor229. The feed motor228is a drive source for rotating the feed roller219, and the transport motor229is a drive source for rotating the transport roller222. The transport motor229is connected to the frictional force application portion220and the discharge roller225, and also rotates the frictional force application portion220and the discharge roller225.

The feed roller219, the transport roller222, and the discharge roller225rotate forward together with the driving of the feed motor228and the transport motor229so as to transport the document D from the upstream side to the downstream side in the feed direction Y1and the transport direction Y2. The frictional force application portion220rotates backward together with the driving of the transport motor229so as to apply a frictional force to the opposite side of the document D from the feed direction Y1. The transport roller222and the discharge roller225rotate faster than the feed roller219, and a transport speed (refer toFIG. 20) Vb at which the transport roller222transports the document D is faster than a feed speed (refer toFIG. 20) Va at which the feed unit218feeds the document D. The transport roller222and the discharge roller225rotate at approximately the same speed, and the discharge speed at which the discharge roller225discharges the document D is approximately the same speed as the transport speed Vb.

The image reading apparatus211is provided with a placement detection unit231and a feed detection unit232. The placement detection unit231is capable of detecting the document D which is placed on the placement portion216, and the feed detection unit232is provided closer to the downstream side in the feed direction Y1than the frictional force application portion220and is capable of detecting the document D which is fed by the feed unit218. The image reading apparatus211is provided with a transport detection unit233, and a rotation detection unit234. The transport detection unit233is capable of detecting the document D which is transported, and the rotation detection unit234detects the number of rotations of the transport roller222. The transport detection unit233is provided at a position between the feed detection unit232and the reading unit224in the transport direction Y2which is substantially the same position as the transport roller222.

Each of the placement detection unit231and the transport detection unit233is a contact sensor which includes a lever, for example, and detects the presence or absence of the document D due to the lever being pushed by the document D. The feed detection unit232is an optical sensor which includes a light emitting unit236which emits light, and a light receiving unit237which receives the light which is emitted from the light emitting unit236. The rotation detection unit234is a rotary encoder, for example, and detects an estimate of an encoder scale238which rotates together with the transport roller222. The image reading apparatus211is provided with a control unit240which performs overall control of the driving of the mechanisms in the image reading apparatus211such as the transport roller222.

As illustrated inFIG. 17, in the feed detection unit232, the light emitting unit236and the light receiving unit237are provided in substantially the same position as the feed roller219in the transport direction Y2so as to face each other interposing the transport path217. The light emitting unit236emits light toward a detection region C on the transport path217, and the light receiving unit237receives the light which passes through the detection region C. Therefore, when the document D is positioned in the detection region C, the light is blocked by the document D, the light reception amount which is received by the light receiving unit237is reduced, and the feed detection unit232detects the document D.

The feed detection unit232is provided such that the detection region C is positioned at a position in the transport direction Y2between the pinching position P1and the intersecting position P2. The pinching position P1is a position at which the feed roller219and the frictional force application portion220pinch the document D. The intersecting position P2is a position closer to the downstream side in the transport direction Y2than the pinching position P1at which a tangential line T of the feed roller219intersects the transport path217in a perpendicular manner.

The tangential line T is a common tangential line which is in contact with both the side surface of the cylindrical feed roller219and the side surface of the cylindrical frictional force application portion220. In other words, the feed detection unit232is provided such that the detection region C is positioned closer to the upstream side in the transport direction Y2than the intersecting position P2which is also an intersecting point between the common tangential line between the feed roller219and the frictional force application portion220and the transport path217.

The feed roller219and the frictional force application portion220are formed of rubber, sponge, or the like, and may elastically deform, for example. In other words, the feed roller219and the frictional force application portion220may come into surface contact. In this case, a downstream end in the transport direction Y2of the surfaces which are contacting each other of the feed roller219and the frictional force application portion220is the pinching position P1, and the feed detection unit232is provided between the pinching position P1and the intersecting position P2. Therefore, the feed detection unit232detects the document D which is past the feed unit218.

Next, description will be given of the electrical configuration of the image reading apparatus211.

As illustrated inFIG. 18, the control unit240controls the driving of the reading units224, the feed motor228, and the transport motor229based on the detection results of the placement detection unit231, the feed detection unit232, the transport detection unit233, and the rotation detection unit234.

Next, with reference to the flowchart illustrated inFIG. 19, description will be given of a transport method of the document D in the image reading apparatus211based on the image reading process routine. The image reading process routine is executed at the timing at which a job of reading an image is input.

As illustrated inFIG. 19, the control unit240drives the feed motor228and the transport motor229in step S501, causes the feed unit218to feed the document D (the feeding process), and causes the transport roller222to transport the document D which is fed (a transport process).

In step S502, the control unit240determines whether or not the transport detection unit233detects the leading end (the downstream end in the transport direction Y2) of the document D. In a case in which the transport detection unit233does not detect the document D (step S502: NO), the control unit240waits while the feed motor228and the transport motor229are still driven.

When the transport detection unit233detects the document D, the control unit240determines that the leading end of the document D is transported to the transport detection unit233(step S502: YES), and in step S503, stops the feed motor228. In step S504, the control unit240causes the reading units224to start reading the image, and in the following step S505, causes the feed detection unit232to detect the rear end of the document D (the rear end detection process).

In other words, in a case in which the feed detection unit232detects the document D, the control unit240determines that the document D is yet to pass the feed detection unit232and waits (step S505: NO). When the detection results of the feed detection unit232change from a state in which the document D is detected to a state in which the document D is not detected, the control unit240determines that the rear end of the document D is detected by the feed detection unit232(step S505: YES). In step S506, the control unit240decelerates the transport motor229, and the transport roller222causes the transport speed Vb at which the document D is transported to slow down (a decelerating process).

In step S507, the control unit240determines whether or not the next document D is placed on the placement portion216based on the detection results of the placement detection unit231. In a case in which the document D is placed on the placement portion216(step S507: YES), the control unit240drives the feed motor228in step S508and transitions the process to step S509. In a case in which the document D is not placed on the placement portion216(step S507: NO), in step S509, the control unit240determines whether or not the rear end of the document D is past the reading units224.

In other words, in a case in which the number of rotations of the transport roller222from when the transport detection unit233detects the rear end of the document D is less than a predetermined number of times, the control unit240determines that the rear end is yet to pass the reading units224and waits (step S509: NO). In a case in which the number of rotations of the transport roller222from when the transport detection unit233detects the rear end of the document D exceeds a predetermined number of times (for example, 0.5 rotations), the control unit240determines that the rear end of the document D is past the reading units224(step S509: YES). The predetermined number of times is set according to the type of the image reading apparatus211, and is a value which is obtained by dividing the distance from the transport roller222to the reading units224by the transport amount of the document D which is transported with a single rotation of the transport roller222.

In step S510, the control unit240ends the reading of the image the reading units224, and accelerates the transport motor229in step S511. In step S512, the control unit240determines whether or not the feed motor228is being driven.

In a case in which the feed motor228is being driven (step S512: YES), in step S513, the control unit240accelerates the feed motor228and transitions the process to step S502. In a case in which the feed motor228is stopped (step S512: NO), in step S514, the control unit240stops the transport motor229and ends the image reading process routine.

Next, regarding the operations of the image reading apparatus211which is configured as described above, description will be given of the operations in a case in which a job of reading an image is input in a state in which two documents D are placed on the placement portion216based on the timing chart ofFIG. 20. The placement detection unit231, the feed detection unit232, and the transport detection unit233output a detection signal S11in a case in which the document D is detected, and output a non-detection signal S12in a case in which the document D is not detected.

As illustrated inFIG. 20, the control unit240drives the feed motor228and the transport motor229at a first timing t1. The feed unit218feeds the document D at a first feed speed Va1, and the transport unit221transports the document D at a first transport speed Vb1.

At a second timing t2, when the transport detection unit233detects the leading end of the document D, the control unit240stops the feed motor228and sets the feed speed Va to zero. Since the transport motor229is being driven at this time, the transport roller222transports the document D at the first transport speed Vb1, and the feed roller219rotates to follow the document D which is transported by the transport roller222. Meanwhile, the frictional force application portion220rotates backward and continues to apply a frictional force to the document D. The reading units224read an image of the document D at the timing at which the document D passes.

When the document D which is transported by the transport roller222passes the pinching position P1, the frictional force which is applied to the document D by the frictional force application portion220stops acting on the document D, and the feed detection unit232detects the rear end of the document D.

At a third timing t3, when the feed detection unit232detects the rear end of the document D, the control unit240decelerates the transport motor229. Specifically, the control unit240decelerates the transport speed Vb at which the transport roller222transports the document D from the first transport speed Vb1to the second transport speed Vb2. The second transport speed Vb2is a speed at which it is possible to nullify changed in the frictional force which occur before and after the rear end of the document D passes the pinching position P1. Therefore, the speed at which the document D passes the reading units224in a case in which the document D to which the frictional force application portion220applies a frictional force is transported at the first transport speed Vb1is approximately the same as the speed at which the document D passes the reading units224in a case in which the document D on which the frictional force of the frictional force application portion220does not act is transported at the second transport speed Vb2.

Since the transport roller222also causes the discharge roller225and the frictional force application portion220to rotate, the discharge roller225decelerates the discharge speed at which the document D is discharged and the rotational speed of the frictional force application portion220in accordance with the transport speed Vb. In other words, the control unit240decelerates the discharge speed in accordance with decelerating the transport speed Vb.

At the third timing t3, since the placement detection unit231detects the next document D, at a fourth timing t4which is reached once a predetermined time is elapsed from the third timing t3, the control unit240drives the feed motor228. The predetermined time is a time which is set according to the type of the image reading apparatus211and the type of the document D, and is set to a time (for example, one second) of a degree at which the document D which is previously fed does not overlap with the document D which is subsequently fed.

At a fifth timing t5, when the transport detection unit233detects the rear end of the document D, the control unit240waits until the rear end of the document D passes the reading units224and accelerates the transport speed Vb and the feed speed Va. Specifically, the control unit240accelerates the transport motor229at a sixth timing t6at which the number of rotations which is detected by the rotation detection unit234exceeds the predetermined number of times after the transport detection unit233detects the rear end of the document D and the rear end of the document D passes the reading units224. In other words, the transport speed Vb is accelerated from the second transport speed Vb2to the first transport speed Vb1.

At a seventh timing t7, when the transport speed Vb reaches the first transport speed Vb1, the control unit240accelerates the feed motor228and accelerates the feed speed Va from the first feed speed Va1to the second feed speed Va2.

At an eighth timing t8, when the transport detection unit233detects the leading end of the document D, the control unit240stops the feed motor228and sets the feed speed Va to zero.

At a ninth timing t9, when the feed detection unit232detects the rear end of the document D, the control unit240decelerates the transport motor229and decelerates the transport speed Vb from the first transport speed Vb1to the second transport speed Vb2. Since the placement detection unit231does not detect the document D at this time, the control unit240does not drive the feed motor228.

At a tenth timing t10, when the transport detection unit233detects the rear end of the document D, the control unit240waits until the rear end of the document D passes the reading unit224, and accelerates the transport motor229at an eleventh timing t11. At a twelfth timing t12, when the transport speed Vb is accelerated to the first transport speed Vb1and the document D is discharged to the discharge portion227, the control unit240stops the transport motor229and sets the transport speed Vb to zero.

According to the embodiment described above, it is possible to obtain the following effects.

(1) Since the control unit240decelerates the transport speed Vb when the feed detection unit232detects the rear end of the document D, changes in the speed at which the document D passes the reading units224are reduced. Therefore, it is possible to reduce changes in the length of the image which is read by the reading units224.

(2) For example, when the previous document D is transported at the slow transport speed Vb and the subsequent document D is transported at the fast transport speed Vb, the subsequent document D may catch up to the previous document D. Addressing this point, since the transport speed Vb is increased once the document D passes the reading units224, it is possible to improve throughput while reducing the influence on the image which is read by the reading units224.

(3) It is possible to accurately acquire the position of the document D in the transport path217based on the detection results of the transport detection unit233and the rotation detection unit234. Therefore, it is possible to reduce the risk of the transport speed Vb being modified before the document D passes the reading units224.

(4) Since the discharge speed is decelerated in accordance with decelerating the transport speed Vb, it is possible to reduce the speed difference between the transport speed Vb and the discharge speed. Therefore, it is possible to favorably perform the transferring of the document D from the transport roller222to the discharge roller225and the transporting of the document D.

(5) When the transport detection unit233detects the rear end of the document D which is previously fed, the control unit240accelerates the feed speed Va. Therefore, it is possible to reduce the speed difference between the feed speed Va and the transport speed Vb. Therefore, it is possible to smoothly transfer the document D which is subsequently fed from the feed unit218to the transport roller222.

(6) For example, when the feed roller219starts rotating at a fast speed, the feed roller219may slip on the document D and be unable to feed the document D. Addressing this point, since the control unit240accelerates the feed speed Va after the feeding is started, it is possible to reduce the risk that the document D cannot be fed.

Furthermore, the embodiment described above can also be modified as described below.

In the embodiment which is described above, the placement detection unit231, the feed detection unit232, the transport detection unit233, and the rotation detection unit234may be arbitrary detection units such as those which use contact and those which do not. For example, the feed detection unit232may be a contact sensor which includes a lever. For example, the transport detection unit233may be an optical sensor. The feed detection unit232and the transport detection unit233may be image sensors which detect the document D using image processing, or ultrasonic wave sensors which detect the document D according to the degree of attenuation of an ultrasonic wave.

In the embodiment which is described above, the first transport speed Vb1may be the same speed as the first feed speed Va1.

In the embodiment which is described above, the control unit240may not accelerate the feed speed Va even if the transport detection unit233detects the rear end of the document D. In other words, the control unit240may not accelerate the feed speed Va at the seventh timing t7indicated inFIG. 20. The control unit240may accelerate the feed speed Va at the fifth timing t5at which the transport detection unit233detects the rear end of the document D, or at the sixth timing t6at which the rear end of the document D passes the reading units224.

In the embodiment which is described above, a configuration may be adopted in which the discharge roller225and the discharge driven roller226are not provided.

In the embodiment which is described above, the discharge speed may be fixed regardless of the transport speed Vb. In other words, the pressure with which the discharge roller225and the discharge driven roller226pinch the document D is set to be weak in comparison with the pressure with which the transport roller222and the transport follower roller223pinch the document D, for example, and in a case in which the transport speed Vb is decelerated, the discharge roller225may be allowed to slip on the document D.

In the embodiment which is described above, a configuration may be adopted in which at least one of the transport detection unit233and the rotation detection unit234is not provided. For example, once a predetermined time is elapsed from when the transport detection unit233detects the rear end of the document D, the control unit240may determine that the rear end of the document D is past the reading units224.

In the embodiment which is described above, the control unit240may not accelerate the transport speed Vb even if the rear end of the document D passes the reading units224. In other words, the control unit240may not accelerate the transport speed Vb at the sixth timing t6and the eleventh timing t11. In a case in which the next document D is fed, the transport speed Vb may be accelerated between the sixth timing t6and the eighth timing t8. At the eleventh timing t11at which the rear end of the last document D passes the reading units224, the transport motor229may be stopped in this state.

In the embodiment which is described above, the frictional force application portion220may be a separation pad which pinches the documents D together with the feed roller219to separate the documents D.

In the embodiment which is described above, the image reading apparatus211is not limited to a sheet feeding type, and may be a flatbed type image reading apparatus which is provided with an automatic document feeding apparatus (an auto sheet feeder) which automatically feeds the documents D. The image reading apparatus211may be applied to a multifunctional device which is configured to be integral with the printing apparatus, a FAX which is provided with a communication function, or the like.