JP2003206054A - Detecting device for double-feeding of paper sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detecting device for paper sheet double-feeding capable of detecting double-feeding independently of thickness of the paper sheets at the time of feeding the paper sheets having various thickness. <P>SOLUTION: This paper sheets double-feeding detecting device is provided with a driving roller 2 provided in a carrying passage 1, a driven roller 3 arranged opposite to the driving roller 2 and to be rotated with the rotation of the driving roller, a first sensor device 4 for detecting the rotation of a driven roller rotary shaft 11 for supporting the driven roller 3, a computing processor for processing the detection information detected by the first sensor device 4, a mechanism 5 for giving the pushing force for pushing the driven roller 3 to the driving roller, a mechanism 6 for giving a rotating load to the driven roller shaft, and a second sensor device 8 for detecting a pass-through of a tip of the paper sheet 10. When the paper sheet 10 passes through between the driving roller 2 and the driven roller 3, a reference value for discriminating one-piece feeding or double-feeding and the detection information obtained by the first sensor 4 are compared with each other to determine the generation of double-feeding. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-feed detection device used in various types of paper sheet processing apparatuses such as an image reading apparatus and a form processing apparatus that handle paper sheets. The present invention relates to a device that can be handled at one time.

[0002]

2. Description of the Related Art In various devices such as an image reading device and a form processing device that handle paper sheets, it is important to separate the paper sheets one by one and take in / carry them into the apparatus. For this reason, a device for separating the paper sheets is provided in the paper feeding section to prevent the occurrence of double feeding (for example, Japanese Patent Laid-Open No. 11-29231).
No. 6 publication).

However, the occurrence of double feeding cannot be completely prevented, and sometimes there is a problem of so-called double feeding, in which two or more sheets of paper are sent to the transport system in a state of being stacked. Therefore, in the conventional apparatus, the double feed detection is performed by a method of measuring the paper thickness and the amount of transmitted light in a conveying path and comparing the obtained information with a reference value (for example, see Japanese Patent Laid-Open No. 5-43091). ).

[0004]

Although the above method has no problem when handling paper sheets having a uniform thickness, a proper reference value is required when handling paper sheets having various thicknesses at one time. In some cases, it cannot be set, and it is extremely difficult to determine whether or not there is a double feed.

Therefore, the present invention has been made in view of the above problem, and when handling paper sheets having different thicknesses at one time, it is possible to detect double feeding without depending on the thickness. An object of the present invention is to provide a double feed detection device for leaves.

[0006]

In order to achieve the above object, according to the present invention, a drive roller provided in a paper path for conveying paper sheets and a drive roller arranged to face the drive roller via the conveyance path, A driven roller that rotates along with the rotation of the drive roller, a first sensor device that acquires the rotational behavior of the driven roller rotation shaft that supports the driven roller, and detection information obtained by the first sensor device. An arithmetic processing unit for processing, a mechanism for applying a pressing force to the driven roller to the driven roller, a mechanism for applying a rotational load to the driven roller shaft, and a second device for detecting passage of the leading edge of the paper sheet. A multi-feed detection device for paper sheets, comprising a sensor device,
The arithmetic processing unit stores a reference value for determining a state of one sheet or double feeding when the paper sheet passes between the drive roller and the driven roller, A double-feed detection device for paper sheets, wherein a double-feed determination is performed by comparing a reference value with the detection information obtained by the first sensor device.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show a double feed detecting device for paper sheets according to a first embodiment of the present invention. 1 and 3 are side views and FIG. 2 is a front view. The multi-feed detection device for paper sheets according to the present embodiment is arranged so as to face a drive roller 2 that drives a paper sheet 10 that is conveyed in a conveyance path 1 and a drive roller 2 through the conveyance path 1. The driven roller 3 that rotates along with the rotation of the drive roller 2, the sensor device 4 (for example, a rotary encoder) that acquires the rotational behavior of the driven roller shaft 11, and the pressing force to the drive roller 2 with respect to the driven roller 3. A mechanism 5 for giving a rotation load, a mechanism 6 for giving a rotational load to the driven roller shaft 11,
The damper unit 7 that suppresses the vibration of the driven roller 3 due to the passage of the paper sheet, and the sensor device 8 (for example, a photoelectric sensor) that detects the passage of the front end of the paper sheet 10 and gives a trigger for measuring the roller rotation behavior are shown in FIG. As shown in FIG. 5, the main body rotating unit 9 is configured so that the entire detecting unit including the driven roller 3 and the like can be separated from the drive roller.

The state of double feed detection in this apparatus is shown in FIG.
4b will be described.

When a paper sheet is conveyed to this apparatus, the sensor device 8 first detects the leading edge of the paper sheet 10 and gives a trigger for measuring the roller rotation behavior (FIG. 4a). The rotation behavior of the driven roller 3 when the paper sheet 10 passes between the drive roller 2 and the driven roller 3 along the transport path 1 is measured by the sensor device 4 which acquires the rotation behavior of the driven roller shaft 11 (FIG. 4).
b).

Since the driven roller 3 is given a rotational load by the mechanism 6 which applies a rotational load to the driven roller shaft 11, the rotational speed of the driven roller 3 is lower than that of the drive roller 2 even when the driven roller 3 is rotated while no paper sheet passes. However, the frictional force generated between the surface of the driven roller 3 and the driving roller 2 and the paper sheet when the paper sheet passes is smaller than the frictional force generated between the drive roller and the driven roller when the paper sheet rotates together. Therefore, the rotation speed is further reduced. Further, when the paper sheets 10 are double fed, the drive roller /
Since the paper sheets / paper sheets / driven rollers overlap,
The number of rotations of the driven roller 3 is further reduced due to a slip between the sheets due to the rotational load on the driven roller 3 and a small fold of the sheet 10 in contact with the driven roller 3. The change in the number of revolutions is acquired by the sensor device 4, and the paper sheet 10 is passed based on the increase in the rotation angle during a certain time while the paper sheet 10 is passing between the drive roller and the driven roller, and the acquired data such as the angular velocity and the angular acceleration. It is determined whether the number of leaves was one or multiple feeding.

An example of the acquired data is shown in FIG. 5 as a conceptual diagram. The data A is the amount of increase in the rotation angle of the driving roller 2, and the data B is the driven roller 3 when the paper sheet 10 is not rotated and is rotated.
Rotation angle increase amount, data C is the rotation angle increase amount of the driven roller 3 at the time of passing one sheet, and data D is the driven roller 3 at the time of double feeding.
Is the amount of rotation angle increase. Here, the mechanism 6 that applies a rotational load to the driven roller shaft 11 may directly contact the driven roller shaft 11 to apply a friction brake, or may use a magnet or the like to apply a non-contact load ( For example, a torque generator) or the like may be used. For example, by setting such acquired data as a reference value and comparing it with the actually measured increase amount of the driven roller rotation angle, it is possible to detect the double feeding of the paper sheets.

Further, an actuator device (not shown) which is provided in parallel with the mechanism 6 for applying a rotational load to the driven roller shaft 11 and changes the magnitude of the rotational load to a predetermined value, and the rotational load of the driven roller shaft 11. A sensor device (not shown) for detecting the data, processing the data obtained from the sensor device,
By providing a control device (not shown) that controls the actuator device, the rotational load is controlled to a desired value, and the contact state between the driven roller 3 and the surface of the paper sheet is controlled to make a determination accuracy. It is also possible to prevent the paper sheet 10 from being damaged and the damage to the paper sheet 10.

The pressing force, the mass of the entire detection unit,
By adjusting the gap between the rollers, the damper, etc., it is possible to increase the rotation angle increase amount during double feeding as compared with the case shown in FIG. Double feeding can be detected by comparing with the value data.

Since the surface material of the driving roller 2 and the driven roller 3 is required to generate a sufficient frictional force between the passing paper sheets, the surface material is more than the frictional force generated between the passing paper sheets. The frictional force generated between the material and the passing paper sheet must be set to be larger. Along with this, the contact area between the roller surface and the paper sheets, that is, the nip is sufficiently secured,
It is necessary to generate sufficient frictional force to obtain the data required for the determination. In this case, not only a pair of the driving roller and the driven roller but also a combination of the roller and the belt or a belt pair may be used. Further, in any combination, the surface materials of the driving roller / belt and the driven roller / belt do not necessarily have to be the same.

Further, the surface shape of the driving roller 2 and the driven roller 3 may be a smooth cylindrical shape, a projection may be provided on the cylindrical surface, or a gear shape.

The mechanism 5 for applying a pressing force to the driven roller 3 against the driven roller 3 may be one which positively applies a force by using a pressurizing spring as shown in FIG. It may be one using itself. Further, this pressing force may be applied via the damper section 7.

Further, the driven roller 2 is different from the driven roller 3
The pressing force between the drive roller 2 and the driven roller 3 and the actuator device (not shown) that is provided in parallel with the mechanism 5 that applies a pressing force to the actuator roller and that changes the magnitude of the pressing force to a predetermined value are detected. By providing a sensor device (not shown) for controlling the actuator device and a controller (not shown) for processing the data obtained from the sensor device and controlling the actuator device, the pressing force between the rollers can be set to a desired value. By controlling the value, it is possible to control the contact state between the driven roller 3 and the surface of the paper sheet to improve the determination accuracy and prevent damage to the paper sheet 10.

The locus of the entire detection portion when it is separated from the drive roller 2 may be an arcuate shape due to the rotational movement as shown in FIG. 3 or may be a linear movement in the vertical direction along a linear guide or the like. It may be separated. Further, in any movement, when separating, it does not matter whether the first separating direction of the trajectory is perpendicular to the common tangent line passing through the contact point between the driving roller 2 and the driven roller 3.

The drive roller 2 and the driven roller 3 do not have to be in contact with each other with the conveyance path 1 of the paper sheet 10 as a common tangent line. For example, the driven roller 3 is shift-disposed upstream or downstream of the conveyance path 1, Alternatively, the tip of the leaf may be guided so as to come into contact with either roller first.

The driving roller 2 and the driven roller 3 do not have to have the same diameter or width. For example, the diameter of the driven roller 3 is increased in order to reduce the collision when the paper sheet plunges between the driving roller and the driven roller, the curvature of the roller is increased with respect to the conveying path 1, and the vibration of the detection unit is suppressed. You may.

Next, an example of the procedure for detecting whether or not there is a double feed is shown in the flowchart of FIG. In step 1, a determination reference value is set, and in step 2, the sensor device placed in front of the detection device senses passage of the leading edge of the paper sheet, and gives a trigger for measuring the roller rotation behavior. Step 3 is a delay process that gives an appropriate measurement start time when the distance between the double feed detection device and the sensor device is large. In step 4, the sensor device actually acquires the rotational behavior of the driven roller shaft. Then, in step 5, the reference value set in step 1 is compared, and if it is determined that there is double feeding, the corresponding processing required in step 6 is performed.

Another example of the procedure for detecting whether or not there is double feed is shown in the flowchart of FIG. In step 1, a determination reference value is set, and in step 2, the sensor device placed in front of the detection device senses passage of the leading edge of the paper sheet, and gives a trigger for measuring the roller rotation behavior. Step 3 is a delay process that gives an appropriate measurement start time when the distance between the double feed detection device and the sensor device is large, and
In fact, the rotation behavior of the driven roller shaft is actually acquired by the sensor device, and in step 5, the reference value set in step 1 is compared, and if it is determined that there is double feed, the corresponding processing required in step 6 is performed. . On the other hand, in step 7, the rotation behavior data obtained in step 4 is stored, and in step 8, statistical processing and the like are performed in real time based on the stored data, and correction processing necessary for the determination reference value set in step 1 is performed. And used as a new criterion value for the next determination. For example, in the example of FIG. 7, among the rotational behavior data obtained in step 4, the data determined to pass one sheet in step 5 is stored in step 7 and used in step 8 for correction of the determination reference value. There is. As an example of the statistical processing in step 8, processing for grasping the tendency of the paper sheets currently flowing in the transport path based on the average of the past data history and the distribution of values is performed, and for example, only thin paper is transported. If
The judgment reference value is corrected in real time so as to improve the judgment performance when a thin paper sheet passes.

In addition, the actual tip of the paper sheet does not pass through the sensor 8 for detecting the passage of the paper sheet, but the sensor device 4 for acquiring the rotational behavior of the driven roller shaft by a soft signal or the like. On the other hand, by directly giving a trigger signal to start the measurement, the rotation angle increase data of the driven roller when the paper sheet is not passed and the rotation angle increase data, etc. are acquired and stored.
Based on the stored data, it is possible to correct the reference value in the determination as to whether or not there is a double feed. For example, the frictional force generated between the surface of the driving roller and the driven roller and the passing paper sheet changes due to the environment in which the double feed detection device is placed, the deterioration of the surface material of the driving roller / driven roller over time, and the contamination. However, even when the acquired data is expected to change, when the paper sheet passes between the rollers, the reference value for determining whether the sheet is a single sheet or multi-feed is corrected in real time. Therefore, it is possible to contribute to improvement of detection / judgment performance, maintenance of the device, judgment of device abnormality / fault, and the like.

As an example of the double feed determination method in step 5 in FIGS. 6 and 7, for example, data C in FIG.
The data 1 and the data 2 of the increase of the rotation angle during the constant time (t ₀ to t _{1 in} FIG. 8) during the passage of the paper sheets between the driving / driven rollers as shown in FIG. 8 corresponding to the data D are actually measured values. Then, the data value θ ₁ of the increase in the rotation angle at t ₁ is compared with the determination reference value θ _S. In the case of the data 1 in FIG. 8, it can be seen that θ ₁ > θ _S and the number of paper sheets that have passed through is one. In the case of data 2 in FIG. 8, θ ₂ <
It can be seen that the paper sheets that have reached θ _{S and} passed through are multi-fed.

As another determination method, for example, a rotational speed or rotational acceleration data sequence of the driven roller is obtained by calculation from a rotational angle increase data sequence obtained as an actual measurement value at a sufficiently high sampling speed and used as a reference value. A comparison method or a data string that determines in advance whether the number of paper sheets passing between the rollers is one sheet or multi-feed is collected at a sufficiently high sampling rate and prepared as a reference data string. A method of comparing the deviation for each sampling time with the data string obtained as the actual measurement value under the same sampling speed condition from the sensor device that acquires the rotational behavior of the driven roller shaft, or the absolute value of the deviation for each sampling time It is possible to use a method of comparing the total sum, variance, etc. with the judgment reference value.

In addition, it is possible to use various pattern recognition methods for the determination. For example, from the increase data string of the rotation angle of the driven roller collected in advance at a sufficiently high sampling speed to the rotation speed or rotation acceleration data string of the driven roller. Is obtained by calculation, a subspace to be used as a criterion for determination is created from these data strings, and a method of determining by comparing the similarity of the data strings obtained as actual measurement values under the same sampling speed condition is used. You may use.

[0028]

As described above, according to the present invention,
A pair of rollers capable of measuring rotation behavior information are provided on a conveyance path for conveying sheets, and the obtained rotation amount and the rotation speed and acceleration of the roller obtained from the rotation amount are input to the arithmetic processing unit. Thus, when handling paper sheets having different thicknesses at a time, it is possible to detect double feeding without depending on the thickness.

[Brief description of drawings]

FIG. 1 is a side view showing a double feed detection device for paper sheets according to a first embodiment of the present invention.

FIG. 2 is a front view showing a double feed detection device for paper sheets according to the first embodiment of the present invention.

FIG. 3 is an explanatory view showing a state in which the entire detection unit such as a driven roller is separated from the drive roller by the main body rotation unit.

FIG. 4 is an explanatory diagram showing a state of double feed detection in this apparatus.

FIG. 5 is a conceptual diagram showing an example of an acquired data string.

FIG. 6 is a flowchart illustrating an example of determination of double-feed detection.

FIG. 7 is a flowchart showing another example of double feed detection determination.

FIG. 8 is a conceptual diagram showing an example of a data string obtained as an actual measurement value.

[Explanation of symbols]

1 Transport Path 2 Drive Roller 3 Driven Roller 4 Sensor Device for Acquiring Rotational Behavior of Driven Roller Shaft 5 Mechanism for Applying Pressing Force to Driven Roller on Driven Roller 6 Mechanism for Applying Rotational Load on Driven Roller Shaft 7 Paper Sheet The damper unit 8 which suppresses the vibration associated with the passage of the sheet 8 The sensor device 9 for detecting the passage of the leading edge of the sheet 9 The main body rotating unit 10 The sheet 11 The driven roller shaft

Continued front page    (72) Inventor Hideki Ogawa             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Ko Ohara             2-9 Suehiro-cho, Ome City, Tokyo Stock Market             Company Toshiba Ome Factory F term (reference) 3F048 AA01 AB01 BA13 CA02 CC07                       EB24

Claims (5)

[Claims] 1. A drive roller provided on a paper sheet conveyance path, a driven roller arranged to face the drive roller via the conveyance path, and a driven roller which is rotated along with the rotation of the drive roller, and the driven roller. A first sensor device that acquires the rotational behavior of a driven roller rotating shaft that supports the roller, an arithmetic processing device that processes detection information obtained by the first sensor device, and the drive roller with respect to the driven roller. A double-feed detection device for paper sheets, comprising a mechanism for applying a pressing force to the paper, a mechanism for applying a rotational load to the driven roller shaft, and a second sensor device for detecting the passage of the leading edge of the paper sheets. The arithmetic processing unit stores a reference value for determining the state of one sheet or multiple feeding when the paper sheets pass between the drive roller and the driven roller. , The reference value and the first sensor Double feed detection device of the paper sheet which is characterized in that the heavy feed determination by comparing the detected information obtained by the location. 2. An actuator device, which is provided together with a mechanism for applying a rotational load to the driven roller shaft, for varying the magnitude of the rotational load to a predetermined value, and a third sensor for detecting the rotational load of the driven roller shaft. The double feed detection of paper sheets according to claim 1, further comprising: a device and a first control device for processing information obtained from the third sensor device and controlling the actuator device. apparatus. 3. An actuator device, which is provided together with a mechanism for applying a pressing force to the driven roller to the driven roller, and which varies the magnitude of the pressing force to a predetermined value, the driving roller and the driven roller. A fourth sensor device for detecting the pressing force between the two, and a second control device for processing the information obtained from the fourth sensor device and controlling the actuator device. The double feed detection device for paper sheets according to claim 1. 4. The arithmetic processing device comprises means for storing the detection information obtained by the first sensor device, and enables correction of the reference value based on the stored detection information. The double feed detection device for paper sheets according to claim 1. 5. The double feeding of paper sheets according to any one of claims 1 to 4, further comprising a damper unit for suppressing vibration of the driven roller due to passage of the paper sheets. Detection device.