JP2011111317A - Sheet feeding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet feeding device, configured so that a document for which double feed occurs during operation of image reading or the like can be distinguished from a document normally subjected to image reading or the like, whereas the occurrence of double feed during feeding of sheets separated from a sheet bundle causes the deterioration in efficiency in continuous image reading operation or the like since the document in the double feed cannot be distinguished. <P>SOLUTION: When double feed of sheets is detected, the discharge rate of the double-fed sheets is changed to a discharge rate differed from that in normal feed to change the landing position thereof, whereby the double-fed sheets are clearly distinguished from sheets without double feed. Further, paper discharge processing is performed so that the landing position is changed according to a user's operation by stopping the conveyance in a state where the rear end of the double-fed sheets approaches a discharge section. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sheet feeding apparatus that continuously feeds and conveys a plurality of sheets such as originals and printing paper such as a scanner, a facsimile, a copying machine, and a printer.

  2. Description of the Related Art Conventionally, some copiers, scanners, printers, and the like are provided with a sheet feeding table (original table) for stacking a plurality of sheet bundles and a sheet feeding device for feeding the stacked sheet bundles in the conveyance direction.

 FIG. 3 is a cross-sectional view showing a typical configuration of the image reading apparatus (see, for example, Patent Document 1). When reading a document, the document placed on the document table 100a is fed and conveyed one by one, and the image is read. The document placed on the document table is sent to the conveyance path by the pickup roller 111. At this time, a certain amount of the document is caused by the feeding force of the pickup roller 111 and the frictional force that the document receives from the inclined surface located at the opposite position. Separation takes place. Further, only the uppermost document is separated from the document bundle and conveyed by the separation roller 114 that rotates in the opposite direction to the feed roller 113 that rotates in the conveyance direction.

With respect to the conveyed document, it is confirmed that only one sheet is properly separated in the conveyance path by the double feed detection sensors 160a and 160b, and the image sensor 140 for reading the front surface and the image sensor for reading the back surface are used. At 150, the image of the original is read.

The document whose image has been read is conveyed to the paper discharge unit, and is detected by the paper discharge sensor 151 and is discharged by the paper discharge roller 124.

If the document separation is not performed correctly and the double feed detection sensors 160a and 160b determine that double feed is performed, for example, as shown in FIG. 4, a plurality of stacked sheets S2 exist in the transport path. Become.

As an example of processing for a document when double feeding occurs, it is conceivable to immediately stop conveyance in the state of FIG. Alternatively, as shown in FIG. 5, processing such as continuing the conveyance of the document S2 that has been double fed and discharging the document S2 to the paper discharge unit may be performed.

JP 2007-266767 A

In the above-described method of stopping conveyance at the time of double feeding, the user needs to open the conveyance path of the apparatus and take out the double-fed original, and much trouble is required until it can be read again. Further, even when the double-fed original is discharged to the paper discharge unit, it is necessary to separate the double-fed original correctly and return it to the paper supply unit again, which is troublesome.

Also, when reading an envelope or a document with a receipt attached, the reading may be performed without the separation function. In such a case, the user changes the setting so as to invalidate the detection of the double feed detection sensor, thereby avoiding detection of double feed when reading these documents.

Except for the special operation mode, in order to prevent reading errors due to double feeding, it is necessary to make the double feed detection sensor perform reading without setting it invalid. However, there are cases where reading is started without noticing that a document bundle that is detected as a double feed as described above is mixed in a large number of document bundles. For this reason, every time a double feed is detected, the user checks whether it is a real double feed or an envelope or a pasted document, and manually returns the double feed document to the paper feed unit. .

In order to simplify this work, for example, in Patent Document 1, when a double feed of a document conveyed to the image reading unit is detected, a part of the double fed document is exposed to the outside of the image reading apparatus. There has been proposed an apparatus for stopping the discharge of a multi-fed original after being transported to a position. In other words, the apparatus stops the discharge operation in a state where the other part of the fed document is held inside the image reading apparatus. However, in the case of such an apparatus, although it is not necessary to perform an operation such as opening the conveyance path of the apparatus, it is necessary to check a document determined to be double-fed each time, and to take out and read it again. , Work efficiency will be reduced. Further, even if the document is not re-read every time double feed is detected, a dedicated storage space is required such as temporarily storing the double-fed document in another location, which is troublesome.

Further, as in an apparatus disclosed in Japanese Patent Application Laid-Open No. 07-160065, for example, a first guide path that guides a document that is not double-fed and a second guide path that guides a double-fed document are provided. Although there is a device, the device itself becomes large and the mechanism becomes complicated, which makes it very expensive.

An object of the present invention is to provide a sheet feeding apparatus capable of solving such problems.

In order to achieve the above object, a sheet feeding apparatus according to the present invention includes a separation feeding unit that separates and feeds sheets, a discharge unit that discharges sheets, a discharge sheet stacking unit that stacks discharged sheets, and a sheet. And a control means for controlling the discharge means, and the control means controls the discharge means and changes the sheet discharge speed based on the detection result of the double feed detection means. It is characterized by doing.

According to the present invention, there is provided a sheet feeding device capable of reliably discriminating between double fed sheets and normally fed sheets when performing an operation of separating and feeding sheets one by one from a sheet bundle. can do.

1 is a diagram for explaining a schematic configuration of an image reading apparatus according to Embodiment 1. FIG. FIG. 6 is a diagram for explaining a schematic configuration of an image reading apparatus according to a second embodiment. It is a figure for demonstrating schematic structure of the conventional image reading apparatus. FIG. 4 is a diagram for explaining the image reading apparatus in a state where sheets are multi-fed. FIG. 6 is a diagram for explaining a state where a sheet is discharged while being double-fed. It is a flowchart which shows the operation | movement in 2nd Example of this invention.

  Embodiments of the present invention exemplified below will be described with reference to the drawings.

An image reading apparatus including a sheet feeding apparatus according to a first embodiment of the present invention will be described with reference to FIG. The document table 1 can be moved up and down substantially vertically, and a user stacks a document bundle (sheet bundle) F on the document table 1. Reference numeral 3 denotes an original detection sensor that detects that the upper surface of the stacked original bundle F has been raised to a predetermined feeding position by the upward movement of the original table 1.

The pickup roller 4 functions as a feeding rotating body. Reference numerals 6 and 7 denote document separating and feeding means disposed downstream of the pickup roller 4 in the document conveying direction. The feeding roller 6 as an upper conveying rotating member and the separating roller 7 as a lower separating rotating member. A pair of rollers.

Image reading sensors 14 and 15 are provided on the upper surface side and the lower surface side of the document conveyed in the conveyance path, and read image information on the upper surface side and the lower surface side of the document, respectively.

The paper discharge sensor 16 detects that the document has passed through the conveyance path of the apparatus and has reached a position where it can be discharged to the paper discharge stacking unit (discharged sheet stacking unit) 44 by the paper discharge roller pairs 26 and 27. The discharge speed by the paper discharge roller pairs 26 and 27 can be changed by controlling the rotation speed of the paper discharge motor 28 by a control circuit (not shown).

The upper guide plate 40 and the lower guide plate 41 constitute a document transport path from the pickup roller 4 to the paper discharge unit 24, and the document is transported along the document transport path.

The transport motor 10 transports the driving side rollers such as the document transport roller pairs 20 and 21, the document transport roller pairs 22 and 23, and the document transport roller pairs 24 and 25 via power transmission means (not shown) such as a gear and a belt. Rotate in the direction. The rotation speed of the transport motor 10 is controlled to be a predetermined rotation speed by a control circuit (not shown) according to the document reading speed, resolution, and the like.

The registration rollers 17 and 18 pass through the separation and conveyance unit composed of the feed roller 6 and the separation roller 7, and the nip between the two rollers in which the leading edge of the original separated and conveyed is temporarily stopped. This function is used to correct the skew of the document once it is received. It also serves to adjust timing such as timing for starting image reading processing by the image reading sensor.

In the image reading by the image reading sensors 14 and 15, the scanning interval is changed based on the resolution of the image set in advance by the user, controlled by a control circuit (not shown). The pre-registration sensor S2 and the post-registration sensor S4 are disposed on the document entrance side and the document exit side of the registration roller pairs 17 and 18, respectively. The double feed detection sensor S3 for detecting the double feed of the document is disposed, for example, at a position between the pre-registration sensor S2 and the pair of registration rollers 17 and 18. The arrangement position of the double feed detection sensor S3 is not limited to this, and a position in the document transport path where the rotation speed of the paper discharge roller can be controlled based on the signal of the double feed detection sensor. Any place is acceptable.

After the document once hits the nip portion of the registration roller pair 17 and 18 and stops, a registration clutch (not shown) is turned on, and the registration roller pair 17 and 18 starts to rotate in the conveyance direction. The pair 20 and 21, the gap between the upper and lower image reading sensors 14 and 15, the transport roller pair 22 and 23, and the transport roller pair 24 and 25 are transported along the transport path in this order to the discharge roller pair 26 and 27. Discharged. When it is determined that the trailing edge of the document has passed the paper discharge sensor 16 and is passing the transport roller pair 24, 25, the paper discharge motor 28 is disabled so as to change the rotation speed of the paper discharge roller pair 26, 27. Control is performed by the control circuit shown in the drawing, and the document is changed to a slower original conveyance speed (first discharge speed) so as to improve the discharge alignment. The shift timing is calculated or estimated from the document detection timing by the post-registration sensor S4, the paper discharge sensor 16, and the like based on the number of pulses of the motor, the transport speed and the transport distance, etc. Then, after the trailing edge of the document has passed through the pair of conveying rollers 24 and 25, it is performed.

For example, when reading a low-resolution monochrome image or the like, if the document conveyance speed of the conveyance unit is high, the document trailing edge passes the conveyance roller pair 24, 25, and the document is nipped only by the discharge roller pair 26, 27. At this point, a process of reducing the rotational speed of the paper discharge roller pairs 26 and 27 to a discharge speed (first discharge speed) with good discharge alignment (deceleration process of acceleration / deceleration process) is performed. . In this way, by setting the discharge speed to a slow speed with good discharge alignment, it is possible to reduce the scattering of the original on the discharge stacking portion 44 that occurs when the original is discharged from the discharge roller pair. The paper discharge alignment is improved.

On the other hand, if the document transport speed of the transport unit is lower than the discharge speed (first discharge speed) with good discharge alignment, for example, when reading a high-resolution color image, the trailing edge of the document is transported. When the original passes between the roller pairs 24 and 25 and the original is sandwiched between the paper discharge roller pairs 26 and 27, the paper discharge speed is increased to achieve a discharge speed with good paper discharge alignment ( Acceleration processing of acceleration / deceleration processing) is performed. By setting an appropriate discharge speed in this manner, the document is landed at an appropriate position when it is discharged from the pair of discharge rollers. The rear end portion of the original is in contact with the lower cover portion of the paper discharge roller and stays in a curved state, thereby eliminating the problem of staying and improving the paper discharge alignment.

By repeatedly executing the above-described series of operations, a process of separating, conveying, and reading the original bundle one by one from the original stack stacked on the original table 1 is continuously executed. Such an apparatus and control method with improved paper discharge alignment are the same as those disclosed in Japanese Patent Application Laid-Open No. 2007-331908.

The process of setting the predetermined discharge speed (first discharge speed) with good discharge alignment by the above-described acceleration / deceleration is performed when double feed is not detected based on the detection result of the double feed detection sensor S3. Is. In the present embodiment, when the conveyed document is determined to be double-fed by the double-feed detection sensor S3, the rotation speed of the paper discharge roller pair 26 and 27 is different from the discharge speed at which the paper discharge alignment is good. Speed (second discharge speed). In this embodiment, the discharge speed is changed to a speed (second discharge speed) that is faster than a speed with good discharge alignment for a document that has been detected as double-feed. By executing the control of the discharge motor 28 by a control circuit (not shown), the leading edge position of the document that has been detected as being double-fed is discharged from the document that is not detected as being double-fed. The discharged originals are stacked in such a state that they protrude beyond the tip position landing on the paper stacking unit.

Conversely, the document transport speed of the transport section is relatively low, and the process for increasing the transport speed to the first discharge speed in order to improve the paper discharge alignment in the paper discharge section is not detected as double feed. In the present embodiment, the second paper discharge speed is higher than the paper discharge speed with good discharge alignment for the paper detected as double feeding in this embodiment. I try to change to speed. By executing the control of the discharge motor 28 by a control circuit (not shown), the leading edge position of the document that has been detected as being double-fed is discharged from the document that is not detected as being double-fed. The discharged originals are stacked in such a state that they protrude beyond the tip position landing on the paper stacking unit. By performing the above-described control, it is possible to easily separate a normally transported document and a double-detected document from a document bundle discharged and stacked on one discharge stacking unit 44. . Further, based on the detection result of the multifeed detection sensor S3, a series of image reading operations can be interrupted by discharging the document while setting the discharge speed to the first discharge speed or the second discharge speed. Since the document can be discriminated clearly and the document that has been double-fed can be clearly identified, the post-processing at the time of double-fed can be smoothly transferred.

In other words, the user who performs the image reading operation only needs to extract only the multi-fed originals from the original bundle and collect them, and collectively execute the image reading operation again for the multi-fed originals. In this way, it is possible to prevent a document whose image has not been read due to double feeding from being processed, and it is not necessary to monitor the image reading operation, and other work can be performed in parallel. Therefore, it is possible to realize an image reading apparatus that can improve the efficiency of business.

The operation of the image reading apparatus according to the second embodiment of the present invention will be described with reference to FIGS. Note that the first embodiment is modified so that post-processing can be selected by a user operation.

  As described in the first embodiment, when transporting a document bundle in which a document on which an envelope, a receipt, or the like is pasted is conveyed, the double feed detection sensor detects a weight on the envelope or the pasted document. Detecting the transmission. In this embodiment, when it is known in advance that pasted originals and the like are mixed with normal originals, double feed is detected because the originals are pasted originals or the like. Thus, the image reading operation can be performed while the user who performs the image reading operation visually judges and selects a treatment each time whether the double feed is detected.

  Further, in this embodiment, an operation unit that reflects the user's judgment as to whether or not to process as multi-feed for use when such a mode is selected is provided in the apparatus main body, and the envelope is based on the operation result. It is also possible to change the document alignment position between the pasted document and the document actually conveyed by double feeding.

As described above in Japanese Patent Application Laid-Open No. 2007-266767, whether or not a document conveyed to the image reading unit is double-feeded is detected by a double-feed detection sensor, and when double-feed of a document is detected, After transporting a part of the multi-fed document until it is exposed to the outside of the image reading apparatus, the discharge of the multi-fed document is stopped while the other part of the multi-fed document is held inside the image reading apparatus. An apparatus is disclosed.

In the present embodiment, when the document is stopped at the time of detecting the double feed in this way, the user operates the operation unit A to select whether or not to process the double feed, and according to the selection result. Added a process to change the discharge speed. When the user who is performing the image reading operation looks at the document stopped during paper discharge and recognizes that it is a double feed because it is a document such as an envelope and should not be processed as a double feed Suppose that the user performs an operation of selecting not to process as double feeding on the operation unit A. In addition, when the user sees the document stopped during paper discharge and recognizes that a real double feed has been detected and is to be processed as a double feed, the user selects an operation to select the double feed. It shall be performed in part A. It is preferable that a display prompting the user to visually confirm the double feed of the stopped document when the document is stopped at the time of detecting the double feed is displayed on a display unit (not shown) such as the operation unit A. is there.

FIG. 6 is a flowchart showing processing executed by a control unit such as a CPU (not shown) provided in a control circuit (not shown). In step S101, it is determined whether or not double feed is detected by the double feed detection sensor. If it is determined that double feeding has not been detected, the paper discharge motor 28 is controlled so as to achieve a discharge speed with good alignment in step S105 to discharge the paper. On the other hand, if it is determined in step S101 that double feeding has been detected, the document continues to be conveyed so that the leading edge of the document is exposed from the paper discharge section and only the trailing edge is held between the discharge roller pairs 26 and 27. At this point, the paper discharge motor 28 is stopped to stop the paper discharge operation (step S102). Next, when it is determined by a user operation on the operation unit A that an operation for selecting not to perform double feed is performed (NO in step S103), a discharge speed with good alignment in the step S105 (first step) The paper discharge motor 28 is controlled so that the discharge speed is reached. In this way, for a document on which the user visually confirms that it should be treated as normal even if double feeding is detected and selects not to process as double feeding, the discharge speed is set to The document is discharged to a normal discharge position at a speed at which the discharge alignment is good, and the process is terminated.

On the other hand, when the user confirms that it is a true double feed by looking at the document stopped during the paper discharge, and determines that the multi-feed processing has been selected by the user operation on the operation unit A (step). In step S103, YES, and in step S104, the paper discharge motor 28 is controlled so that the discharge speed (second discharge speed) is higher than the normal discharge speed, and the paper is discharged. In other words, it is determined that a document selected by the user to be processed as a double feed is to be discharged at a high speed so that the leading edge of the document is protruded from other normal transported documents. The original is discharged and the process is terminated. If necessary, the process may proceed to the next document reading process or the like in a state where the document is discharged to a discharge position different from the normal discharge position.

In this embodiment, when a double feed of a document is detected during conveyance, the discharge speed is changed to a second discharge speed that is slower than the first discharge speed, and the document is discharged while being slowly discharged at the second discharge speed. The user can confirm whether or not the double feed is made visually. In addition, it is preferable to display a message on a display unit (not shown) such as the operation unit A so that the user can visually confirm whether or not the double feed. Or you may make it prompt the user to confirm whether it is double feeding using LED etc. which are not illustrated. Alternatively, the user may select a very slow discharge speed (second discharge speed) or an unnaturally changing discharge speed (second discharge speed: the average speed is slower than the first discharge speed). An abnormality in the discharging state may be felt, and the user may be prompted to confirm whether or not double feeding is performed. In any of the above cases, when it is determined that the user who has visually confirmed that the document is being double fed while the document is slowly being discharged has operated the operation unit A or the like, the discharge can be controlled to be interrupted. Is preferred. Alternatively, when it is determined that an operation of the operation unit A or the like has been performed by a user who has visually recognized double feeding while the document is slowly being discharged, the discharge speed is higher than the normal discharge speed. It may be discharged and the multi-fed document may be landed far away.

In each of the above embodiments, the control of the rotation speed of the paper discharge roller may be realized not by control of the paper discharge motor but by switching of a power transmission mechanism such as a gear. Further, in the second and third embodiments, the user operation input is not performed by the operation unit provided in the apparatus main body, but may be performed by the user operating a host device such as a PC connected to the image reading apparatus. Good. In this case, an image reading system including an image reading device and a host device such as a PC connected to the image reading device corresponds to the image reading device of the present invention.

As described above, the sheet feeding device of the present invention is a device that discharges a sheet that has been normally fed and a sheet that has been double fed onto the same paper stacking unit, and is based on the presence or absence of double feed detection. Was changed. As a result, it is possible to sort documents that have been detected to be double-fed, and a user who performs an image reading operation can quickly sort a multi-fed document, and can perform operations without interrupting a series of image reading operations. . In addition, although the paper discharge unit has a simple configuration, the separation can be realized by controlling the rotation speed of the paper discharge roller, so that it is possible to realize a compact and inexpensive sheet feeding apparatus that does not require an extra space. .

14 Image reading sensor 15 Image reading sensor 26 Paper discharge roller 27 Paper discharge roller 28 Paper discharge motor 44 Paper discharge stacking unit S3 Double feed detection sensor

Claims (7)

Separation feeding means for separating and feeding sheets;
Discharging means for discharging the sheet;
A discharge sheet stacking unit for stacking discharged sheets;
A double feed detecting means for detecting double feed of the sheet;
Control means for controlling the discharging means,
The sheet feeding apparatus according to claim 1, wherein the control unit controls the discharge unit to change a sheet discharge speed based on a detection result of the double feed detection unit. When the double feed detection means does not detect the double feed of the sheet, the control means controls the discharge means to discharge the sheet at the first discharge speed,
When double feeding of the sheet is detected by the multifeed detection means, the control means controls the discharge means to discharge the sheet at a second discharge speed different from the first discharge speed. The sheet feeding apparatus according to claim 1, wherein the sheet feeding apparatus can be used. Further comprising an operation means for accepting a user operation to change control of the discharge means by the control means
In a case where double feeding of the sheet is detected by the double feeding detecting means, the discharging means holds a part of the sheet where double feeding is detected and exposes a part of the sheet. The control means controls the discharge means so as to stop the paper discharge operation.
The control means controls the discharge means based on a user operation from the operation means, and sets the discharge speed of the sheet detected to be double-fed to either the first discharge speed or the second discharge speed. The sheet feeding device according to claim 2, wherein the sheet feeding device is determined as follows. The second discharge speed is higher than the first discharge speed, and the discharge position of the sheet discharged at the second discharge speed is higher than the discharge position of the sheet discharged at the first discharge speed. The sheet feeding device according to claim 2, wherein the sheet feeding device is at a downstream position. Further comprising an operation means for accepting a user operation to change control of the discharge means by the control means
When the double feed detection means does not detect the double feed of the sheet, the control means controls the discharge means to discharge the sheet at the first discharge speed,
When double feeding of the sheet is detected by the double feeding detection means, the control means controls the discharging means to discharge the sheet at a second discharging speed that is slower than the first discharging speed. At the same time, during the discharge of the sheet at the second discharge speed, the control means controls the discharge means based on the user operation to interrupt the discharge of the sheet or to discharge faster than the first discharge speed. 2. The sheet feeding apparatus according to claim 1, wherein the sheet is discharged at a speed. An image reading apparatus comprising the sheet feeding apparatus according to claim 1. Separation feeding means for separating and feeding sheets;
Conveying means for conveying the sheet;
Discharging means for discharging the sheet;
A discharge sheet stacking unit for stacking discharged sheets;
A method for controlling a sheet feeding apparatus provided with a double feed detecting means for detecting double feeding of sheets,
A control method for a sheet feeding apparatus, comprising: a step of controlling the discharge unit so as to change a sheet discharge speed based on a detection result of the double feed detection unit.

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