JP2000165594A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relieve the job load by the operator and to enhance an image read efficiency by continuing reading without stopping paper feeding even on the occurrence of double feeding and recovering only a defect of reading due to the double feeding after the end of the reading. SOLUTION: In this image reader, even when double feed sensors 8a, 8b discriminate double feeding of paper A fed from a hopper 1, driving of a carrying path is continued, and the double feeding paper A is marked by a double feeding index print section 11 after image reading by a read section 10 or a counter counts at which order number of the paper the double feeding takes place to recover the double feed part and only the double feeding paper A is sorted from the paper normally fed and then ejected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus such as an image scanner, and more particularly to a double feed detecting function for detecting a double feed when two or more sheets of a read original have been fed. The present invention relates to an image reading device.

[0002]

2. Description of the Related Art An image reading apparatus such as an image scanner is provided with a paper feeding device for feeding a sheet set on a hopper to a line. This sheet feeder feeds out stacked sheets one by one from the top, and most of the sheet feeders have a double feed prevention mechanism in which two or more sheets are sent out by friction between overlapping sheets. As a paper feeder having such a double feed prevention mechanism, for example, there is a paper feeder disclosed in Japanese Patent Laid-Open No. 4-286558, and a combination of a separation roller and a retard roller having a built-in torque limiter is widely used. I have.

On the other hand, when a double feed of sheets occurs, the two sheets pass through the image reading section while overlapping each other, so that the reading of the image described on the sheet is inferior. For this reason, it is necessary to detect the double feed of the sheet between the hopper and the image reading unit, and an optical sensor or an ultrasonic sensor is conventionally used as a detection method. In the case of using an optical sensor, roughly speaking, the distance between the leading edge and the trailing edge of the paper is calculated by detecting the length of the paper in the feeding direction, and when this distance is larger than the length of the paper, the weight is reduced. This is a method of determining transmission. In the case of using an ultrasonic sensor, an ultrasonic transmitter and a receiver are arranged with a paper conveyance path interposed therebetween, and the ultrasonic wave attenuation to the receiving side when one sheet of paper passes is referred to. When the degree of attenuation becomes larger than this, it is determined to be a double feed.

With the introduction of such an optical sensor or an ultrasonic sensor, it is possible to determine whether the sheet before entering the image reading section is in a single-sheet or multi-feed state, and it is possible to effectively prevent the image reading failure or missing of the sheet. You. Conventionally, when a double feed of paper is detected, the feed from the hopper is stopped immediately and a warning of the occurrence of double feed is generally issued. In other words, when double feeding of paper occurs, the paper feed is stopped before proceeding to the image reading process, so that the operator is prompted to reset without wasteful image reading from the paper in the double feeding state, and the double feeding occurs. It is convenient to restart image reading from the used paper.

[0005]

An image reading device used as a dedicated device is often used for inputting a large amount of documents as an input device such as an electronic filing device or an OCR. It takes a considerable amount of time to complete reading of all sheets after setting. For example, the processing capability of the current image reading device is 1
Although it is set to about 40 sheets per minute, it takes 25 minutes or more to input 1000 sheets or more. For this reason, after the sheet is set, the operator can go to another job, return to the apparatus after estimating the completion time, set another sheet again, and start reading again. With this configuration, the sheet reading operation by the image reading device and other tasks can be performed in parallel.

However, if double feeding of paper occurs during the image reading process, paper feeding is stopped as described above, and the operator returns to the apparatus for resetting and removes the paper or restarts operation. It is necessary to check whether double feeding of paper has occurred. For this reason, the parallel work is interrupted for the operator,
This leads to a decrease in work efficiency.

[0007] The image reading apparatus itself also
Since the operation is temporarily stopped every time double feeding occurs, a decrease in the operating rate is inevitable, and the work efficiency when processing a large amount of paper is greatly reduced, and the work load on the operator is also increased.

As described above, in the conventional image reading apparatus,
Since the sheet feeding is stopped every time double feeding occurs, it tends to hinder the parallel operation of the operator and reduce the efficiency of image reading itself.

The problem to be solved in the present invention is that, even when a double feed occurs, the reading is continued without stopping the sheet feeding, and after completion, only the defective reading caused by the double feed is collected and the reading operation is performed again. And to improve the efficiency of image reading.

[0010]

According to the present invention, there is provided a paper feed unit for feeding stacked original sheets in a single-sheet feed, a double feed detecting unit for detecting double feed of two or more sheets of paper, and the paper feed unit. An image reading apparatus comprising: a reading unit that optically reads an image drawn on the sheet; and a conveyance path that conveys the sheet to a discharge end, wherein when double feeding is detected by the double feeding detecting unit, It is characterized by including a control system for discriminating or sorting the multi-fed paper and non-multi-fed paper while discharging the paper while continuing to drive the transport path.

In such a configuration, all the sheets set in the sheet feeding section are processed irrespective of the occurrence of double feed.
This eliminates the need for a reset operation when double feeding occurs, and identifies or sorts non-multi-fed paper for multi-fed paper, making it easy to check only multi-fed paper. The work load until the reading is performed again is also reduced.

[0012]

According to a first aspect of the present invention, there is provided a paper feed unit for feeding sheets of stacked originals in a single-sheet feed, and a double feed detecting unit for detecting double feed of two or more sheets. An image reading device comprising: a reading unit that optically reads an image drawn on the sheet; and a conveyance path that conveys the sheet to a discharge end, wherein a multi-feed is detected by the multi-feed detection unit. An image reading apparatus including a control system for discharging the multi-fed paper while discriminating or sorting the non-multi-fed paper while continuing to drive the conveyance path,
Even when the frequency of double feeding is high, the work load on the operator is small, and the operation rate is increased to improve the efficiency of image reading.

According to a second aspect of the present invention, as a means for discriminating the multi-fed paper and the non-multi-fed paper, the back side of the multi-fed paper is operated based on the multi-feed determination by the multi-feed detecting unit. 2. A printing device for marking a double feed index on a sheet.
The image reading device described above has an effect that a multi-feed sheet can be easily confirmed by a marked multi-feed index.

According to a third aspect of the present invention, as the means for discriminating the multi-fed paper and the non-multi-fed paper, the number of sheets read by the reading means is counted, and the multi-feed detecting unit detects 2. The image reading apparatus according to claim 1, further comprising a counter that outputs a count value of the multi-fed sheet, wherein the multi-feed sheet can be generally identified by referring to the count value output from the counter, and the non-multi-fed sheet can be identified. Has the effect of facilitating the extraction of

According to a fourth aspect of the present invention, there is provided the image reading apparatus according to the first aspect, wherein the image reading apparatus includes both the printing means according to the second aspect and the counter according to the third aspect. Since the sheet can be extracted after knowing the approximate position of the multi-feed sheet and then confirmed by the double-feed index, it is possible to specify and extract the multi-feed sheet more reliably.

According to a fifth aspect of the present invention, as the means for sorting the multi-fed paper and the non-multi-fed paper, the non-multi-fed paper which is branched in the middle of the conveyance path and downstream of the reading unit is provided. The first discharge path for paper and the second discharge path for multi-feed paper are disposed at a branch point between the first discharge path and the second discharge path, and the first discharge path side is normally opened. 2. The image reading apparatus according to claim 1, further comprising a gate, wherein the gate includes a control system that closes the first discharge path and opens the second discharge path only when the multi-feed detection is performed by the double-feed detection unit. In addition, since only the multi-fed paper can be collected from the second discharge path, there is no need to remove the non-multi-fed paper from the non-multi-fed paper, so that the operation load of the operator can be further reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a main part of an image reading apparatus having a double feed detection function according to the present invention, and shows a conveyance path of a sheet discharged from a hopper via a reading section and an arrangement of auxiliary devices.

In FIG. 1, a paper feed roller 1a is arranged on a hopper 1 on which sheets A are stacked and mounted, and a separation roller 2a and a retard roller 2b are arranged on the downstream side and above and below a transport path. The hopper 1 is elastically urged clockwise by a spring (not shown) with the right end in the figure as a pivot point in the drawing, as is well known in the art, so that the uppermost sheet A can be fed out by abutting the sheet feeding roller 1a. Things. The hopper 1 is provided with a paper detection sensor 1b for detecting whether or not the paper A is loaded, and can feed paper only when the loading of the paper A is detected.
Similarly, the separation roller 2a and the retard roller 2b can also use conventional ones as they are, and the operation of the torque limiter built in the retard roller 2b allows the hopper 1 to operate.
To prevent double feeding of the paper A.

Downstream of the separation roller 2a and the retard roller 2b, a pair of drive rollers 3a and 3b for receiving and transporting the sheet A fed from the hopper 1 are arranged in three stages in the direction of the transport path, and the last stage drive roller 3a , 3b, a gate 4 for switching between two transport directions is arranged. A pair of feed rollers 5a and 5b are arranged in three stages in the transport direction in a first discharge path which is a path formed in an arc shape upward from the gate 4, and the discharge rollers 6a and
6b is provided. On the other hand, a second discharge path formed as another conveyance path from the gate 4 includes a driving roller 3.
A single-stage discharge roller 7a, 7b is provided so as to be included in substantially the same transport surface as that of the transfer rollers a, 3b.

Incidentally, the gate 4 normally opens the first discharge side and closes the second discharge path side. As will be described later, the gate 4 has a function of sending the multi-fed paper A to the second discharge path side. For example, the gate 4 has a function of discharging thick paper straight without bending it. be able to.

Between the separation roller 2a and the retard roller 2b and the first-stage drive rollers 3a and 3b, there is provided a double feed detecting portion for detecting double feed of paper. As described in the conventional example, the double-feed detection unit can use the double-feed detection sensors 8a and 8b using an optical system or ultrasonic waves. A reading unit sensor 9 for detecting the leading end of the sheet A and inputting the detection time to the controller is provided in front of the second-stage driving rollers 3a and 3b.

Second and third drive rollers 3a, 3b
A reading unit 10 that reads an image from the sheet A is disposed between the two. In the illustrated example, the reading unit 10
In order to read both the front and back surfaces of the optical disk, scanning heads 10a and 10b using optical systems are arranged above and below the transport path.

Further, discharge rollers 6a and 6b
In the first discharge path, a multi-feed index printing unit 11 for printing on the back side of the multi-fed paper A, a printing unit sensor 12
And The multifeed index printing unit 11 prints a mark on the back surface of the paper A determined to be multifeed, indicating that the paper A has been multifeed, and the printing timing is determined by the printing unit sensor 12. The detection time of the leading end position of the sheet A is set as a reference.

FIG. 2 is a block diagram of the operation of the image reading apparatus according to one embodiment of the present invention, and FIG. 3 is a flowchart of the control.

As shown in FIG. 2, the control block includes:
A multi-feed detection unit including a paper detection sensor 1b and multi-feed detection sensors 8a and 8b, a reading unit sensor 9, a reading unit 10,
A transfer control unit 13a for sending and receiving signals between the double feed index printing unit 11 and the printing unit sensor 12 to control the operation of the transfer system from the hopper 1 to the discharge rollers 6a, 6b and the discharge rollers 7a, 7b, A control unit 13 for controlling is provided. The reading unit 10 is connected to a host computer (not shown) and outputs an image signal read from the sheet A.

In the above configuration, during the period in which the paper detection sensor 1b detects that the paper A is loaded on the hopper 1, the transport control unit 13a controls the paper feed roller 1a and the transport of the paper A. The driving of all the rollers is controlled. Then, for the paper A fed from the hopper 1, the double feed detection sensors 8a and 8b first determine the double feed.

When there is no double feeding of the sheet A, the reading unit 10 is operated based on the time when the leading edge of the sheet A is detected by the reading unit sensor 9 to read an image from the sheet A. After this reading, the paper A
The paper is sent by the discharge rollers 6a and 6b without being printed by the double feed index printing unit 11 as a sheet.

On the other hand, when the double feed of the sheet A is detected by the double feed detection sensors 8a and 8b, the reading by the reading unit 10 is executed based on the detection time by the reading unit sensor 9 as in the case without the double feed. . That is,
The sheet A is conveyed toward the discharge rollers 6a and 6b without stopping the conveyance system of the sheet A even when there is a double feed of the sheet A. Then, based on the time when the leading edge of the paper A is detected by the printing unit sensor 12, a mark indicating multifeed is printed on the back surface of the lower paper A among the two overlapping papers A. You.

The two sheets A in the double feed state are discharged outside from the discharge rollers 6a and 6b, and are stacked and collected on a tray. Therefore, after the reading operation for all the sheets A placed on the hopper 1 is completed, the back side of the read sheets A collected on the tray is checked,
It is possible to know which paper has been multi-fed. The double-fed sheet A is placed on the hopper 1 and fed again to read the image.

After all the sheets A on the hopper 1 have been processed by ignoring the double feed on the sheet A as described above,
Only the multi-fed sheet A can be read again. For this reason, when a large amount of paper A is loaded on the hopper 1 to perform a reading operation, the operator can perform other tasks in parallel for the reading time, and the workability is improved. Further, the image reading apparatus itself continues to operate without being stopped every time double feeding occurs, so that the operation rate is also improved.

In the above-described embodiment, in order to know the multi-fed sheet A, it is necessary to check whether or not there is a mark indicating multi-feed on all the collected sheets A on the tray. On the other hand, by counting the number of sheets from the first sheet A first fed out from the hopper 1 and detecting the number of sheets when double feeding occurs, the sheet after reading is read. It is not necessary to check A one by one. FIG. 4 is an operation block diagram for confirming the multi-feed sheet by such counting, and FIG. 5 is a flowchart of the control.

The configuration of the image reading apparatus is different only in that a counter 14 is provided in place of the double feed index printing unit 11 and the printing unit sensor 12 in the above example. The counter 14 counts the number of sheets of paper A read through the detection of the sheet A by the reading unit sensor 9 or the reading operation by the reading unit 10, and the counted number is read by the host computer (not shown) through the reading unit 10. Is input to

Even with such a counter 14, the paper A fed from the hopper 1 is
First, a double feed is determined by a and 8b. Then, when there is no double feed, after the image is read by the reading unit 10 as it is, the feed rollers 5a, 5b and the discharge rollers 6a,
6b discharges to the tray side. Further, even when it is determined that there is a double feed, the feeding of the sheet A from the hopper 1 is continued without stopping.

Here, the counter 14 counts the sheets fed from the hopper 1 sequentially from the first sheet. Therefore, when the number of sheets of paper A counted by the counter 14, that is, the number of sheets read by the reading unit 10, is n, the multifeed detection sensor 8 for the next (n + 1) th sheet A
When it is determined that the multi-feeding is performed by a and 8b, n already counted in the image reading stage is output to the host computer, and 1 is added to the counted number of sheets A by the counter 14 for the multi-feeded paper A. Add. Then, the host computer stores the value of n, and stores the count number of the paper A at the time of the multifeed by the same operation for the multifeed generated in the subsequent supply of the paper A.

After all the sheets A on the hopper 1 have been read, the number of the sheet A in which double feeding has occurred is stored as a count number. Paper A that has been multi-fed. Therefore, it is not necessary to check all of the sheets A that have been read and collected on the tray side, and the multi-feeded sheets A can be easily reprocessed.

It is to be noted that the number of sheets A to be multi-fed is not limited to two, but may be three or more.
If frequent double feeds occur until you finish reading the
The number of counts by the counter 14 and the actual multi-fed paper A
May shift. However, since the number of sheets of paper A in one reading operation is large, even if it is not possible to specify the exact number of sheets, it is sufficient to grasp the number of sheets, and there is no practical problem.

Further, the configuration of FIG. 2 and the configuration of FIG. 4 may be combined. That is, the multi-feed index printing unit 11, the printing unit sensor 12, and the counter 14 are provided,
After the paper A is extracted based on the count value of the multi-fed paper, it is possible to confirm whether a mark indicating the multi-fed is printed on the back surface of the paper A. In this way, even when the paper A is roughly extracted based on the count value of the counter 14, it is possible to reliably select only the paper that is actually multi-fed by the multi-feed mark.

As described above, the double feed index printing unit 11 marks the back of the paper A and counts the number of double feeds, so that the operator can collect the double feed paper A and read it again. Thus, the image reading of all the sheets A can be performed. However, in either case, manual operation by the operator is required, and time is required for checking and removing the multi-feed paper.

Therefore, in the present invention, when a double feed is detected, two or more sheets A
With respect to the above, although the reading by the reading unit 10 is executed, the paper A in the multi-feed state is ejected without being discharged from the discharge rollers 6a and 6b to the tray. This ejecting operation can be performed by the gate 4 already described with reference to FIG. 1 and the discharge rollers 7a and 7b of the second discharge path disposed downstream of the gate 4, and the operation of the gate 4 causes the sheet A to move to the tray side and the eject side. Will be described with reference to FIGS. 1 and 6.

The gate 4 in FIG. 1 has its left end rotatably mounted by a pin or the like and is connected to the output shaft of a motor 4a for rotational driving. The transport controller 13 shown in the block diagrams of FIGS.
The motor 4a is controlled by a so that the gate 4 can be set to the attitude shown in FIGS.

That is, in FIG. 1, the right end side of the gate 4 is connected to the third-stage drive rollers 3a and 3b and the discharge rollers 7a.
The transfer surface between the nip portions a and 7b cuts downward and is inclined downward. Therefore, the driving roller 3
The leading end of the sheet A that has passed through the nip portions of the feed rollers 5a and 5b follows the inclination of the gate 4 ascending to the left.
To the discharge path. On the other hand, in FIG. 6, the right end side of the gate 4 rotates obliquely upward to open the gap between the nip portions of the drive rollers 3a, 3b and the discharge rollers 7a, 7b, and at the same time, the transfer path to the feed rollers 5a, 5b side close.
For this reason, the leading end of the sheet A that has exited the drive rollers 3a and 3b is sent to the discharge rollers 7a and 7b along the lower surface of the gate 4.

By providing such a gate 4, when the paper A fed from the hopper 1 is not multi-fed, the gate A is kept in the posture shown in FIG. The sheet is discharged toward the tray by the discharge rollers 6a and 6b. Then, the double feed detection sensors 8a, 8b
When it is determined that the paper A has a double feed, the operation of the motor 4a is controlled by the transport control unit 13a.
The gate 4 rotates counterclockwise from the state of FIG. 1 and is set to the posture of FIG. By controlling the change of the posture of the gate 4 so that the leading end of the multiply fed paper A reaches the gate 4, the multiply fed paper A is conveyed from the gate 4 to the discharge rollers 7a and 7b. Switch to the road.

As described above, when the paper A is not multi-fed, the paper A can be fed to the tray. When the paper A is multi-fed, the eject operation is performed immediately instead of the tray.
Therefore, it is possible to sort the non-multi-fed sheets and the multi-fed sheets simultaneously with the reading operation. For this reason, it is not necessary to check the multi-fed paper or to select the paper that has not been multi-fed, thereby reducing the work load on the operator.

In FIGS. 1 and 6, for simplicity of explanation, the configuration including both the multifeed index printing unit 11 and the gate 4 is described. And any one of the sorting processes may be used. Of course, it is also possible to adopt a configuration having both of them. For example, even if the paper A is fed into the first discharge path with the gate 4 malfunctioning during the double feeding, the double feeding index printing unit 11
, It is possible to extract multi-feed paper.

[0045]

According to the present invention, the driving of the transport path from the paper feeding unit to the discharge end is continued without stopping even if the multi-feed occurs in the paper fed from the paper feeding unit. The reading time is shortened as compared with the process interrupted every time, and the work load is reduced without restraining the operator from the start to the end of the process.

Further, the multi-feed paper included in the paper layer after the reading is completed can be easily taken out by referring to the marking by the multi-feed index printing unit and the count value by the counter, and the paper is reset every time the multi-feed is performed. The working time is greatly reduced as compared with the case of performing. In particular, in a configuration in which only the multi-feed paper is ejected, the operation of selecting the multi-feed paper is not required, so that the work load is further reduced and the work efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a main part of an image reading apparatus having a double feed detection function according to the present invention, showing a configuration of a sheet conveyance path and double feed detection.

FIG. 2 is an operation block diagram of double feed detection for marking on the back surface of the double feed paper.

FIG. 3 is a flowchart of an operation block diagram of FIG. 2;

FIG. 4 is an operation block diagram of an example in which the number of sheets read by a reading unit is counted to detect the number of sheets when double feeding occurs.

FIG. 5 is a control flowchart of the operation block diagram of FIG. 4;

FIG. 6 is a schematic diagram of a main part showing an example of ejecting a multi-feed sheet by switching a gate.

[Explanation of symbols]

 Reference Signs List 1 hopper 1a paper feed roller 1b paper detection sensor 2a separation roller 2b retard roller 3a, 3b drive roller 4 gate 4a motor 5a, 5b feed roller 6a, 6b discharge roller 7a, 7b discharge roller 8a, 8b double feed detection sensor 9 reading unit Sensor 10 Reading unit 10a, 10b Scanning head 11 Double feed index printing unit 12 Printing unit sensor 13 Control unit 13a Transport control unit 14 Counter A paper

Claims (5)

[Claims] A sheet feeder for feeding the sheets of the stacked originals in a single-sheet feed, a double feed detector for detecting the double feed of two or more sheets, and an image drawn on the sheet optically. And a transport path for transporting the sheet to a discharge end, wherein when the double feed detection unit detects double feed, the drive of the transport path is continued. An image reading apparatus that includes a control system for discharging or discriminating or sorting a multi-fed sheet from a non-multi-fed sheet while discharging. 2. A multi-feed index is marked on the back side of the multi-fed paper as a means for discriminating the multi-fed paper from the non-multi-fed paper based on a multi-feed determination by the multi-feed detection unit. The image reading device according to claim 1, further comprising a printing unit. 3. A means for discriminating between the multi-fed paper and the non-multi-fed paper, counting the number of sheets read by the reading means and determining whether the multi-fed paper has been multi-fed by the multi-fed detection unit. The image reading device according to claim 1, further comprising a counter that outputs a count value. 4. An image reading apparatus according to claim 1, comprising both the printing means according to claim 2 and the counter according to claim 3. 5. A first discharge path for a non-multi-fed paper that is branched in the middle of the conveyance path and downstream of the reading section as means for sorting the multi-fed paper and the non-multi-fed paper. And a second discharge path for the multi-feed paper, the first discharge path and the second discharge path.
A gate which is disposed at a branch point with the discharge path and normally opens the first discharge path side, and the gate closes the first discharge path only at the time of the double feed determination by the double feed detection unit and The image reading apparatus according to claim 1, further comprising a control system for opening the second discharge path.