JP2005035756A - Sheet handling device and image reading device - Google Patents

Sheet handling device and image reading device Download PDF

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Publication number
JP2005035756A
JP2005035756A JP2003275916A JP2003275916A JP2005035756A JP 2005035756 A JP2005035756 A JP 2005035756A JP 2003275916 A JP2003275916 A JP 2003275916A JP 2003275916 A JP2003275916 A JP 2003275916A JP 2005035756 A JP2005035756 A JP 2005035756A
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Japan
Prior art keywords
sheet
sensor
registration roller
state
fed
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JP2003275916A
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Japanese (ja)
Inventor
Shunichi Hirose
Kazuhide Sano
一秀 佐野
俊一 広瀬
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Nisca Corp
ニスカ株式会社
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Priority to JP2003275916A priority Critical patent/JP2005035756A/en
Priority claimed from US10/892,364 external-priority patent/US7425001B2/en
Publication of JP2005035756A publication Critical patent/JP2005035756A/en
Pending legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To provide a sheet handling device capable of accurately performing whether or not sheets stacked on a sheet stacker are correctly fed one by one (sheet double feeding).
SOLUTION: A sheet stacker, a separating unit for separating and feeding out the sheets stacked on the sheet stacker, a registration roller for correcting a skew state of the sheet fed from the separating unit, the separating unit and the resist An ultrasonic sensor composed of a wave transmission sensor and a wave reception sensor disposed in an inclined state with respect to the sheet running surface between the rollers, and a sheet double feed state is determined based on an output signal from the wave reception sensor. A discriminator and a controller for controlling rotation of the registration roller and stopping the driving. The discriminating unit outputs an output signal of the wave receiving sensor when a predetermined time elapses after the driving is started after the registration roller is stopped. The multi-feed state of the sheet is determined based on the above.
[Selection] Figure 3

Description

  The present invention relates to a sheet handling apparatus including a sheet separating unit that separates sheets stacked on a sheet stacker one by one and feeds them to the downstream side. In particular, whether or not two or more fed sheets are fed out in a superimposed manner is determined. The present invention relates to a sheet handling apparatus and an image reading apparatus to be detected.

  An image reading apparatus that separates sheets (cut sheets, plastic sheets, etc.) stacked on a sheet stacker one by one and reads an image of each sheet is mounted on a copying machine or a facsimile machine. In a copying machine, sheets (sheets) are separated from a sheet cassette one by one and supplied to a printing unit so that characters and figures are printed on the sheet.

  As described above, reliably separating and feeding out the sheets stacked on the sheet stacker such as a document tray or a paper cassette one by one is extremely important in a sheet handling apparatus that performs a document image reading process, a printing process, and the like. It has become a technical element.

  Therefore, in an automatic document feeder (hereinafter referred to as “ADF”) that feeds sheets one by one from a sheet stacker (sheet feeding tray), the sheets stacked on the sheet stacker are separated one by one. A sheet separation mechanism is provided. Patent Document 1 discloses an example of such a sheet separation mechanism.

  In the sheet separating mechanism disclosed in Patent Document 1, a feeding roller 18 that can be moved up and down is brought into contact with the uppermost sheet of the sheets stacked on the sheet stacker 11 to feed out a document (sheet). The sheet feeding roller 19 feeds only one upper surface and the separation pad 20 that prevents the second and lower originals from being fed out.

  However, the sheets stacked on the sheet stacker (especially in the case of documents) may be bent at the ends or bound by clips, staples, etc., and are provided with the sheet separation mechanism as described above. However, the sheets are not necessarily separated and fed out one by one. For this reason, it is necessary to detect whether the sheets are normally fed out one by one or two or more sheets are overlapped (referred to as “multiple feeding” in the present application).

  In order to detect such a double feed state of a sheet, it is conventionally known to use an ultrasonic sensor.

  In Patent Document 2, an ultrasonic wave propagation axis 10 composed of an ultrasonic transmitter 11 disposed above a moving surface 13 of an object 14 to be detected and an ultrasonic receiver 16 disposed below is provided on the moving surface 13. By tilting it, a stable amount of ultrasonic waves is measured by the ultrasonic receiver 16.

Also, Patent Document 3 is installed in a registering device provided in a portion for delivering a sheet fed from a sheet feeding unit to a post-processing device, and is disposed on the lower side across the sheet. An ultrasonic two-sheet detection method is disclosed in which an ultrasonic wave is applied obliquely to a sheet to be detected in an ultrasonic two-sheet detector including a sensor 23 and a receiving sensor 24 disposed below.
JP 2001-354339 A Japanese Utility Model Publication No. 6-49567 JP-A-6-72591

  However, for example, when handling a sheet that is thin and vibrates in the vertical direction or flutters when traveling, such as thin paper, the ultrasonic sensor can be used to accurately detect the double feed state of the sheet. The timing at which data is received is extremely important technically.

  In particular, since the air gap generated between the sheets is an important factor for the accurate double feed detection of the sheet by the ultrasonic sensor, the sheet is moved to the running surface after the gap is once created between the sheets. If it can be detected in a state of being stretched parallel to the sheet, it is possible to accurately detect the double feed state of the sheet.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet handling apparatus capable of accurately performing whether or not sheets stacked on a sheet stacker are correctly fed one by one (sheet double feeding).

  Therefore, the present invention provides a sheet stacker, a separating unit that separates and feeds out the sheets stacked on the sheet stacker, a registration roller that corrects a skew state of the sheet fed from the separating unit, and the separating unit. And an ultrasonic sensor comprising a wave transmission sensor and a wave reception sensor arranged in an inclined state with respect to the sheet running surface between the registration rollers, and a sheet double feed state based on an output signal from the wave reception sensor Discriminating means for discriminating between the registration roller and the control means for controlling rotation of the registration roller and stopping the driving of the registration roller. The sheet handling apparatus is characterized in that the multi-feed state of the sheet is determined based on the output signal.

  As described above, in this sheet handling apparatus, the ultrasonic sensor including the transmission sensor and the reception sensor is disposed in an inclined state with respect to the sheet traveling surface between the separating unit and the registration roller, and is skewed in the registration roller. When the condition is corrected, an air gap is temporarily generated between the sheets, and then the double feed state of the sheet is determined based on the output signal of the wave receiving sensor when a predetermined time elapses after the drive start-up from the registration roller stop state By doing so, it is possible to accurately detect the double feed state of the sheets.

  Here, the wave receiving sensor is disposed on the upper side of the sheet traveling surface between the separating unit and the registration roller, and the wave transmitting sensor is disposed on the lower side of the sheet traveling surface. It is excluded that dust such as paper dust falls on the sensor surface of the wave receiving sensor and the detection accuracy deteriorates with time.

  In addition, the determination unit can more reliably determine whether the sheet fed from the separation unit is double-fed before the trailing edge of the sheet passes the registration roller. This makes it possible to detect double feeds.

  When the determination unit determines that the sheet fed from the separation unit is double-feed, the subsequent sheet supply from the sheet stacker is stopped.

  The present invention further includes a sheet stacker, separation means for separating and feeding out the sheets stacked on the sheet stacker, a registration roller for correcting a skew state of the sheet fed from the separation means, and the registration roller. A conveying unit that conveys the fed sheet to a reading position, an optical reading unit that reads the sheet conveyed to the reading position, and an inclined state with respect to a sheet traveling surface between the separating unit and the registration roller. An ultrasonic sensor composed of a transmitted wave sensor and a received wave sensor, a discriminating means for discriminating a double feed state of the sheet based on an output signal from the received wave sensor, and rotation control for stopping and driving the registration roller. Control means for performing, and the determination means when the predetermined time has elapsed from the start of driving from the stop state of the registration roller There is provided an image reading apparatus and discriminates double feed state of the sheet based on the output signal of the wave sensor.

  Here, when the determination unit determines that the sheet fed from the separation unit is double feeding, the image reading of the sheet by the optical reading unit is stopped, or all the sheets placed on the sheet stacker are stopped. This is displayed after the reading of the sheet is completed.

  This sheet handling device is able to accurately detect the double feed state of sheets even when handling sheets that are thin and thin, such as thin paper, that vibrate vertically or flutter when traveling. It is.

  In this sheet handling apparatus, since the wave receiving sensor is disposed on the upper side of the sheet running surface, dust such as paper dust on the sheet falls on the sensor surface of the wave receiving sensor and time elapses. At the same time, the deterioration of the detection accuracy of the double feed state was prevented. This is because the transmission sensor has a larger ultrasonic vibration on the sensor surface than the reception sensor, so that the sensor surface is mounted inclined with respect to the plane perpendicular to the direction of gravity. This is because dust such as paper dust easily falls from the sensor surface.

  In addition, it is possible to detect double feed more reliably by continuously determining whether or not the sheet fed from the separating means is double feed before the trailing edge of the sheet passes the registration roller. It was.

  Hereinafter, the details of the present invention will be described based on the drawings.

  FIG. 1 shows a configuration example of an ADF 10 that is one embodiment of a sheet handling apparatus according to the present invention. In FIG. 1, the ADF 10 is mounted on an image reading apparatus 20 and allows a sheet (original) to pass through the upper surface of the platen 12 of the apparatus main body 20. The image reading apparatus 20 irradiates a sheet with light from a light source 21 that constitutes an optical reading unit disposed below the platen 12, and uses a mirror 22 or a prism to reflect the reflected light to a CCD (not shown). By guiding, the image on the sheet is converted into an electric signal in the CCD.

  The image reading device 20 also includes a second platen 13 having an area where the entire surface of the sheet can be placed, and the image of the sheet placed on the upper surface of the platen 13 can be read by opening and closing the ADF 10. ing.

  The ADF 10 includes a sheet stacker 11 on which a plurality of sheets can be placed, a feeding roller 1 that picks up the sheets stacked on the sheet stacker 11 and feeds them downstream, and a sheet fed by the feeding roller 1. Separating means 2 that separates the sheets one by one and feeds them toward the platen 12, a registration roller pair 5 that corrects the skew state of the sheet fed from the separating means 2, and a separation means 2 and a registration roller pair 5. The ultrasonic sensor 3 for detecting the double feed state of the sheet fed from the separating means 2 and the first transport for allowing the sheet fed from the registration roller pair 5 to pass through in a state of contacting the upper surface of the platen 12. A pair of rollers 6, a second pair of conveyance rollers 7 that receive the sheet that has passed through the upper surface of the platen 12 and convey it to the downstream side, and the second conveyance roller A discharge roller pair 8 to discharge onto the sheet delivery stacker 14 is conveyed from the roller pair 7, and a.

  Further, a registration sensor 4 is installed on the upstream side of the registration roller pair 5 so as to detect the timing at which the leading edge of the sheet fed from the separating means 3 arrives at the registration roller pair 5.

  The ultrasonic sensor 3 includes a wave transmission sensor 3a and a wave reception sensor 3b, and is disposed in a state of being opposed to each other while being inclined with respect to the sheet traveling surface between the separating unit 2 and the registration roller pair 5. . A wave transmission sensor 3a is disposed below the seat travel surface, and a wave reception sensor 3b is disposed above the seat travel surface.

  The ADF 10 further includes a switchback path 14 that is switched back in the discharge path from the platen 12 to the discharge stacker 14 and is sent again to the registration roller pair 5 and fed to the upper surface of the platen 12.

  The sheet stacker 11 is inclined above a predetermined angle and is disposed above the discharge stacker 14. The sheet placed on the sheet stacker 11 is regulated by a side guide 24 that regulates the side portion thereof. The sheet is placed in a state where the leading end is pushed in such a manner that the leading end of the sheet comes into contact with the leading end portion 11 a of the sheet stacker 11. And the sheet is fed downstream (separating means 2 side). At this time, the number of sheets fed out is not necessarily one.

  The separating means 2 feeds the sheet fed from the feeding roller 1 to the downstream side, and prevents the feeding of the second and subsequent sheets on the lower side through only one uppermost sheet. And a separation roller 2b. The separation roller 2b is stopped when the sheet is fed out, thereby preventing the second and lower sheets from being fed out. Accordingly, instead of the separation roller 2b, a non-rotating separation pad may be used.

  The sheet that has passed through the separating means 2 is sent to the next registration roller pair 5 side. The registration roller pair 5 is stopped when the leading edge of the sheet fed from the separating unit 2 hits the registration roller pair 5 and is driven to rotate after a predetermined time after the leading edge of the sheet arrives at the registration roller pair 5. . As a result, the sheet once forms a loop state between the registration roller pair 5 and the separating means 2 and the leading ends thereof are aligned. As a result, the skew state of the sheet is corrected.

  In the present ADF 10, the separation roller 3b constituting the separation means and one drive roller 5a of the registration roller pair 5 are configured to be driven by a single feeding drive motor (not shown). When the feeding drive motor is controlled to rotate in the forward direction, the separation roller 3b is driven to rotate and the registration roller pair 5 is stopped. When the feeding drive motor is controlled to rotate in the opposite direction, the separation roller 3b is stopped and the registration roller is stopped. The pair 5 is rotationally driven.

  In the present ADF, as will be described in detail later, the ultrasonic sensor 3 discriminates the double feed state of the sheet once the sheet forms a loop between the registration roller pair 5 and the separating means 2 and then the registration roller. After the pair 5 is rotationally driven from the stop, this is performed based on the output signal of the wave receiving sensor 3b after the loop state is canceled. This realizes accurate detection of the double feed state of the sheet.

  The sheet fed from the registration roller pair 5 is supplied to the first transport roller pair 6 and is transported by the first transport roller pair 6 so as to run in a state of being in contact with the upper surface of the platen 12. The sheet is optically read by the optical reading means arranged below the sheet.

  In the single-sided reading mode, the sheet on which the image on one sheet surface is optically read is discharged onto the discharge stacker 14 by the second conveying roller pair 7 via the discharge path 23. In this case, it is switched back by the reverse rotation drive of the discharge roller pair 8 and sent out again to the registration roller pair 5 via the switchback path 24. For this reason, a flapper 29 is provided at the intersection of the discharge path 23 and the switchback path 24. The flapper 29 is always urged downward by an urging spring (not shown). When the sheet is sent along the discharge path 23 to the discharge roller pair 8, the flapper 29 is moved upward by the leading end of the discharged sheet. When the sheet is switched back by the discharge roller pair 8, the discharge path 23 is positioned below to close the discharge path 23 and guide the sheet to the switchback path 24. .

  FIG. 2 shows the change in the state of the sheet between the separating means 2 and the registration roller 5 and the arrangement relationship of the ultrasonic sensors 3.

  As described above, the ultrasonic sensor 3 includes the transmission sensor 3 a and the reception sensor 3 b, and face each other in an inclined state with respect to the sheet traveling surface between the separating unit 2 and the registration roller pair 5. Arranged in a state. A wave transmission sensor 3a is disposed below the seat travel surface, and a wave reception sensor 3b is disposed above the seat travel surface.

  The reason why the ultrasonic sensors 3 are arranged in a state of being opposed to each other while being inclined with respect to the seat traveling surface is to stabilize the amount of ultrasonic waves received by the wave receiving sensor 3b. If the transmission sensor 3a and the reception sensor 3b are arranged so as to oppose each other at a position perpendicular to the sheet running surface, the amount of ultrasonic reception greatly fluctuates due to slight distortion generated on the sheet surface. End up. This is because the double feed state of the sheet cannot be accurately detected.

  In addition, the wave receiving sensor 3b is disposed above the sheet running surface, because dust and dirt such as paper dust accumulate on the sensor surface that receives the ultrasonic wave, thereby degrading accurate detection of the ultrasonic wave reception amount. It is for preventing.

  In FIG. 2, the registration roller pair 5 is controlled to stop when the leading edge of the sheet P fed out from the separating unit 2 arrives. For this reason, as shown in FIG. 2A, the sheet P fed out from the separating unit 2 is further pushed out by the separating unit 2 after the leading end of the sheet P hits the registration roller pair 5, thereby forming a loop state. To do. This loop shape is unsuitable for detecting the double feed state of the sheet because the size (diameter) of the loop fluctuates or fluctuates.

  Next, when a predetermined time elapses after the leading edge of the sheet P hits the registration roller pair 5, the registration roller pair 5 that has been stopped is activated. At the same time as the registration roller pair 5 is started, the separation roller 2a constituting the separation means 2 is stopped, so that the loop shape is gradually extended and the loop state is eliminated. FIG. 2B shows a state in which the sheet P once looped is linearly extended with respect to the running surface between the separating unit 2 and the registration roller pair 5. This time is the most suitable timing for detecting the double feed state of the sheet P. At this time, since the sheet P is nipped by the separating means 2 and the registration roller pair 5, the sheet P does not vibrate up and down or flutter. Furthermore, if the sheet P is in a double feed state, an air gap is generated between the sheets when the loop state shown in FIG. 2A is formed, and the ultrasonic wave is attenuated by this air layer. Therefore, the ultrasonic sensor 3 can accurately detect the double feed state of the sheet.

  FIG. 2C shows a state in which the sheet P is further conveyed downstream by the registration roller pair 5 and the rear end thereof leaves the nip of the separation roller 2. In this state, the sheet P moves up and down around the nip point of the registration roller pair 5 and flutters. Therefore, based on the output signal of the wave receiving sensor 3b at this time, the double feed state of the sheet is determined. It cannot be detected accurately.

  FIG. 3 is a flowchart for explaining the timing of reading the output signal of the wave receiving sensor 3b constituting the ultrasonic sensor 3. The flowchart of FIG. 3 will be described with reference to FIG.

  The sheet fed from the feeding roller 1 passes through only one uppermost sheet in the separating unit 2 and is sent out to the next registration roller pair 5 side so as to prevent the second and subsequent sheets from being fed out. (S1). Since the registration roller pair 5 is stopped when the leading edge of the sheet fed from the separating unit 2 hits the registration roller pair 5, the sheet forms a loop in the registration roller pair 5 (S2). The separation rollers 2a and 2b constituting the separation unit 2 are stopped at this time, and the separation of the sheet ends (S3).

  Next, the registration roller pair 5 is rotationally driven a predetermined time after the leading edge of the sheet arrives at the registration roller pair 5. Thus, the sheet feeding is started (S4), and the loop state formed while the registration roller pair 5 is stopped is canceled (S5). Thereby, the skew state of the sheet is also corrected. At this time, the output signal of the wave receiving sensor 3b constituting the ultrasonic sensor 3 is read (S6).

  In this way, the double feed state of the sheet is determined based on the output signal of the wave receiving sensor 3b when the loop state in the registration roller pair 5 of the sheet is canceled (S7). At that time, the operation of the ADF is stopped (S9). Here, even if the double feeding of the sheets is detected, the reading of the sheets may be continued and a display to that effect may be displayed after the reading of all the sheets is completed.

  Further, when the double feed of the sheet is not detected, until the trailing end of the sheet passes the separating means 2 (S8), the determination of the double feed state of the sheet based on the output signal of the wave receiving sensor 3b is performed. By performing continuously (repeating operation of S6 and S7), a more accurate double feed state of the sheet is detected.

  Then, when the trailing edge of the sheet exits the separating means 5, the sheet is fed downstream (S10), and the next sheet is continuously fed and separated.

  FIG. 4 shows an example of a timing chart in the control of the image reading apparatus 20 equipped with the ADF 10.

  4, the sheet stacker 11 (FIG. 1) is provided with a sheet placement detection sensor (not shown) for detecting whether or not a sheet is placed, and the sheet is placed on the sheet stacker 11. When the image reading start button of the image reading apparatus 20 is pressed in this state, a sheet feeding start signal rises to start sheet feeding.

  The feeding roller 1 contacts the uppermost sheet on the sheet stacker 11 and feeds the sheet by rotating the feeding driving motor (not shown) in the forward direction in response to the rising edge of the sheet feeding start signal. The separation roller 2a is driven to rotate. At this time, the ultrasonic sensor 3 is also in an operating state.

  When the separation motor 2a starts to rotate in this manner, the leading edge of the sheet arrives at the position of the registration sensor 4. The separation roller 3a continues to rotate and stops only for a predetermined time after the registration sensor 4 detects the leading edge of the sheet. During this time, since the registration roller pair 5 is stopped, the sheet is blocked by the registration roller pair 5 to form a loop shape, and the skew state is corrected.

  Thereafter, at a predetermined timing, a feeding drive motor (not shown) is reversely rotated, whereby the registration roller pair 5 starts to rotate. Since the separation roller 2a is stopped simultaneously with the start of the rotation driving of the registration roller pair 5, the sheet loop state (registration loop) is gradually eliminated. Since the registration loop is canceled after a predetermined time has elapsed since the rotation of the registration roller pair 5 is started, the output signal of the wave receiving sensor 3b constituting the ultrasonic sensor 3 is read at that time.

  In the present invention, based on the output signal in this state, it is determined whether or not the sheet is in a double feed state. The output signal of the wave receiving sensor 3b is read continuously until the trailing edge of the sheet leaves the nip of the separating unit 2, so that the double feed state of the sheet is accurately determined.

  Image reading is started a predetermined time after the leading edge of the sheet that has passed through the registration roller pair 5 is detected by a lead sensor 9 (see FIG. 1) disposed upstream of the image reading position, and a CCD (optical reading means). The output signal is taken into the memory. At the same time, the next sheet stacked on the sheet stacker 11 is fed out.

  FIG. 5 shows a configuration example of a control circuit for processing the signal of the ultrasonic sensor 3 using a block diagram.

  As described above, the ultrasonic sensor 3 includes the transmission sensor 3a and the reception sensor 3b. As illustrated in FIG. 5, the transmission sensor 3a includes an ultrasonic wave generated by the ultrasonic oscillation circuit 31. It is driven by an amplifier circuit 32 that amplifies the signal. Here, the gain (amplification factor) of the amplification circuit 32 that amplifies the ultrasonic signal oscillated by the ultrasonic oscillation circuit 31 is configured to be arbitrarily adjustable by the CPU 33. For this reason, the CPU 33 and the amplifier 32 are connected via the D / A converter 38. As a result, the output level of the ultrasonic wave emitted from the wave transmission sensor 3a can be freely set, so that variations in sensor (element) sensitivity, the installation angle with respect to the seat running surface, the distance from the wave reception sensor 3b, and the like can be adjusted. It is possible to set appropriate conditions for the double feed state of the sheet.

  On the other hand, the output signal of the wave receiving sensor 3b is amplified by an amplifier circuit 34 having a predetermined gain, and the electric signal amplified in the smoothing circuit 35 is rectified and smoothed by an integrating circuit having a predetermined time constant. The electrical signal that has passed through the smoothing circuit 36 is compared with a reference value set in advance in the comparison circuit 37. The comparison value output from the comparison circuit 37 is input to the CPU 36 to determine whether or not the sheet is double-fed. As described above, such multifeed determination is continuously performed from the time when the loop formation of the sheet between the separating unit 3 and the registration roller pair 5 is released until the trailing edge of the sheet leaves the nip of the separating unit 3. Done. This enables accurate sheet double feed detection.

  FIG. 6 shows a waveform example of an output signal of the wave receiving sensor 3b together with a reference value. Here, FIG. 6A shows the case of properly one sheet, and FIG. 6B shows the case of the double feed state. FIG. 6A shows that the output value of the wave receiving sensor 3b exceeds the reference value and that only one sheet has been properly fed out. In FIG. 6B, the output of the wave receiving sensor 3b is shown. The value is below the reference value, indicating that the sheet has been double fed.

  In FIG. 6, the waveform of the output signal of the wave receiving sensor 3b is divided into three sections [A], [B] and [C]. The section [A] indicates that the sheet is in a loop state (the state shown in FIG. 2A) and the level of ultrasonic waves received by the wave receiving sensor 3b is unstable. The section [B] is a loop state. Indicates that the front and back of the sheet are nipped by the separating means 3 and the registration roller pair 5 (the state shown in FIG. 2B), and the output signal of the wave receiving sensor 3b is stable. In section [C], when the rear end of the sheet leaves the separating means 3 (the state shown in FIG. 2C), the rear end of the sheet vibrates and the output signal of the wave receiving sensor 3b is slightly unstable. It shows that there is.

  In the present invention, since the sheet double feed state is determined based on the output signal of the wave receiving sensor 3b in the section [B], accurate sheet double feed detection is realized.

  As described above, the present application relates to a sheet stacker, a separating unit that separates and feeds the sheets stacked on the sheet stacker, a registration roller that corrects a skew state of the sheet fed from the separating unit, and the separation An ultrasonic sensor comprising a wave transmission sensor and a wave reception sensor disposed in an inclined state with respect to the sheet running surface between the means and the registration roller, and a sheet double feed based on an output signal from the wave reception sensor A discriminating unit for discriminating the state; and a control unit for controlling rotation of the registration roller and stopping the driving. The double feed state of the sheet is determined based on the output signal of the sensor.

  Therefore, the present invention can be applied not only to ADF that conveys an original sheet to an image reading position, but also to a sheet handling apparatus in general provided in a copying machine that feeds sheets one by one from a sheet stacker and supplies them to a printing unit. Needless to say.

  The sheet handling apparatus according to the present invention includes a sheet separating unit that separates the sheets stacked on the sheet stacker one by one and feeds them downstream, and a detection unit that detects whether the sheets are reliably separated and fed out. Therefore, the present invention has industrial applicability.

The structural example of ADF which is one aspect of the sheet handling apparatus which concerns on this invention is shown. The change in the state of the sheet between the separating means and the registration roller in the sheet handling apparatus and the arrangement relationship of the ultrasonic sensors are shown. The flowchart for demonstrating the timing which reads the output signal of the wave receiving sensor which comprises an ultrasonic sensor is shown. An example of a timing chart in the control of an image reading apparatus equipped with an ADF is shown. The block diagram of the configuration of the control circuit for processing the signal of the ultrasonic sensor is shown. An example of the waveform of the output signal of the receiving sensor is shown together with a reference value.

Explanation of symbols

1: Feeding roller 2: Separating means 2a: Feeding roller 2b: Separating roller 3: Ultrasonic sensor 3a: Wave sending sensor 3b: Wave receiving sensor 4: Registration sensor 5: Registration roller pair 6: First conveying roller pair 7 : Second conveying roller pair 8: Discharge roller pair 9: Lead sensor 10: ADF (sheet handling device)
12: Platen 13: Second platen 20: Image reading device

Claims (7)

  1. A sheet stacker,
    Separating means for separating and feeding out the sheets stacked on the sheet stacker;
    A registration roller that corrects a skew state of the sheet fed from the separating unit;
    An ultrasonic sensor comprising a wave transmission sensor and a wave reception sensor arranged in an inclined state with respect to a sheet running surface between the separation means and the registration rollers;
    Discriminating means for discriminating the double feed state of the sheet based on an output signal from the wave receiving sensor;
    Control means for performing rotation control of stopping and driving of the registration roller,
    The discriminating unit discriminates a double feed state of the sheet based on an output signal of the wave receiving sensor when a predetermined time elapses after driving is started from a stop state of the registration roller.
  2. The wave receiving sensor is disposed above the sheet traveling surface between the separating unit and the registration roller, and the wave transmitting sensor is disposed below the sheet traveling surface, respectively. The sheet handling apparatus according to 1.
  3. The determination unit continuously determines whether or not the sheet fed from the separation unit is double-fed until the trailing edge of the sheet passes the registration roller. The sheet handling apparatus according to 1.
  4. 4. The sheet supply from the sheet stacker thereafter is stopped when the sheet fed from the separating unit by the determining unit is determined to be double feeding. 5. The sheet handling device described.
  5. A sheet stacker,
    Separating means for separating and feeding out the sheets stacked on the sheet stacker;
    A registration roller that corrects a skew state of the sheet fed from the separating unit;
    A conveying means for conveying the sheet fed from the registration roller to a reading position;
    Optical reading means for reading the sheet conveyed to the reading position;
    An ultrasonic sensor comprising a wave transmission sensor and a wave reception sensor arranged in an inclined state with respect to a sheet running surface between the separation means and the registration rollers;
    Discriminating means for discriminating the double feed state of the sheet based on an output signal from the wave receiving sensor;
    Control means for performing rotation control of stopping and driving of the registration roller,
    The image reading apparatus according to claim 1, wherein the determination unit determines the double-feed state of the sheet based on an output signal of the wave receiving sensor when a predetermined time has elapsed after the driving is started from the stop state of the registration roller.
  6. 6. The image reading apparatus according to claim 5, wherein when the sheet fed from the separating unit is determined to be double-fed by the determining unit, the image reading of the sheet by the optical reading unit is stopped.
  7. When the determination unit determines that the sheet fed from the separation unit is double feed, the display unit displays a display to that effect after reading all the sheets placed on the sheet stacker. An image reading apparatus according to claim 5.
JP2003275916A 2003-07-17 2003-07-17 Sheet handling device and image reading device Pending JP2005035756A (en)

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Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2003275916A JP2005035756A (en) 2003-07-17 2003-07-17 Sheet handling device and image reading device
US10/892,364 US7425001B2 (en) 2003-07-17 2004-07-16 Sheet handling apparatus and image reading apparatus
CNB2004100690713A CN100353739C (en) 2003-07-17 2004-07-16 Sheet handling apparatus and image reading apparatus

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Cited By (4)

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JP2006312527A (en) * 2005-05-09 2006-11-16 Konica Minolta Business Technologies Inc Sheet duplicate feed detecting method and paper feeder
JP2008162776A (en) * 2006-12-28 2008-07-17 Mitsubishi Electric Corp Brake testing device for elevator and its testing method
JP2010269893A (en) * 2009-05-21 2010-12-02 Kyocera Mita Corp Image forming device
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JP2008162776A (en) * 2006-12-28 2008-07-17 Mitsubishi Electric Corp Brake testing device for elevator and its testing method
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