JP6497223B2 - Sheet transport device - Google Patents

Description

  The present invention relates to a sheet conveying apparatus that conveys a sheet such as a document.

2. Description of the Related Art A document reading apparatus such as a scanner is provided with a sheet conveying apparatus that conveys an original to a reading position along a conveyance path by a plurality of conveyance rollers.
In such a sheet conveying apparatus, a document with a sticky note may be conveyed. This sticky note can be forgotten to be removed by the user, or it can be left attached without being removed.

  Patent Document 1 discloses a configuration in which a sticky note is detected by an ultrasonic sensor during conveyance of a sheet to which a sticky note is attached, and the user is notified that the sticky note has been detected.

JP 2007-331909 A

In most cases, only a part of a sticky note attached to an original is attached to the original with a small adhesive force so that it can be easily peeled later. Therefore, if the sticky note is in contact with any one of the transport rollers during transport of the original with the sticky note attached thereto, the sticky note is likely to be peeled off or bent by the rotational driving force of the transport roller.
In particular, when a sticky note is peeled off from a document, it remains on the transport path of the document, and the sticky note remaining on the transport path comes into contact with another document transported thereafter, preventing the transport of the document, There is a risk of jamming.

  In order to prevent such peeling of a sticky note and occurrence of a document jam, it is conceivable to prevent the document from being conveyed when it is detected that a sticky note is attached to the document. However, if the sticky note is not in contact with the transport roller during document transport, the sticky note will not be peeled off due to the contact with the transport roller, and the document jam will not occur. The document transportability is degraded.

In the above description, an example in which an original is conveyed by an original reading device has been described. However, the present invention is not limited to this. For example, when an image forming apparatus such as a printer conveys paper to be printed, There is a risk of peeling or paper jamming.
The present invention has been made in view of the above problems, and peeling of a sheet piece or a sheet caused by contact between a sheet piece such as a tag or tag attached to a sheet such as a document or paper and a conveyance roller An object of the present invention is to provide a sheet conveying apparatus capable of preventing the occurrence of a jam or the like during conveyance.

  In order to achieve the above object, a sheet conveying apparatus according to the present invention is a sheet conveying apparatus that conveys a sheet along a conveying path by a plurality of conveying rollers, and is provided on the surface of the sheet by conveying the sheet to be conveyed. When it is predicted that the attached sticky note, a sheet piece such as a tag will be in contact with any of the plurality of transport rollers, and the predicting means is not expected to be in the contact state, When the conveyance of the sheet is performed by the rotation of the conveyance rollers and the contact state is predicted, the sheet of the conveyance rollers is prevented from being conveyed by the stop of the conveyance rollers. And a control means for controlling the rotation.

Further, the control unit may interrupt the conveyance of the sheet when it is predicted that the contact state occurs after the conveyance of the sheet is started.
Here, a notification means for notifying a user of predetermined information is provided, and when the conveyance of the sheet is interrupted, the control means indicates that the conveyance of the sheet is interrupted due to adhesion of the sheet piece as the predetermined information. The notification means may be notified.

Here, the prediction unit includes a position detection unit that detects a position of the sheet piece attached to the surface of the sheet on the sheet, and the control unit determines the detection position of the sheet piece as the predetermined position. The notification means may be notified as information.
In addition, the control unit, after interrupting the conveyance of the sheet, rotates each of the conveyance rollers in a direction opposite to the rotation direction during the conveyance, thereby moving the sheet toward the position before the conveyance starts in the sheet conveyance direction. It may be conveyed in the opposite direction.

  Further, each of the plurality of transport rollers includes a roller having a plurality of roller bodies provided in the width direction at intervals along a rotation axis along a width direction orthogonal to the sheet conveyance direction, and a rotation shaft. One of the conveying rollers provided with two roller bodies, and is arranged at intervals along the sheet conveying direction, and on the conveying path from the upstream side of the sheet conveying direction along the sheet conveying direction. There is a first region where any one of the roller bodies exists at any position up to the downstream side, and a second region where any of the roller bodies does not exist at any position, the predicting means, During the conveyance of the sheet, the sheet piece having at least a part in the first area is positioned most upstream in the sheet conveyance direction among the roller bodies existing in the first area. A sheet piece detecting means for detecting upstream of the sheet conveying direction with respect to the roller body, and the contact state is not established until the sheet piece is detected, and the contact state is detected when the sheet piece is detected. It is also possible to predict that it will be.

  Here, a tray on which sheets are placed, a feeding roller that feeds sheets one by one from a bundle of a plurality of sheets placed on the tray to the downstream side in the sheet conveying direction, and sheet conveyance from the feeding rollers A sheet feeding roller that is disposed at a position downstream of the feeding roller and closest to the feeding roller, and further feeds the sheet fed by the feeding roller to the downstream side in the sheet feeding direction on the feeding path, the feeding roller, Not included in the plurality of transport rollers, the paper feed roller is one of the plurality of transport rollers, is located on the upstream side in the sheet transport direction than the other transport rollers, the sheet piece detection means, A predetermined position downstream of the feeding roller in the sheet conveying direction and upstream of the sheet feeding roller in the sheet conveying direction. The unloading position, when the sheet fed by said feed roller passes, may perform the detection.

The sheet piece detecting means includes a transmitter that emits ultrasonic waves and a receiver that receives the ultrasonic waves emitted from the transmitter, and the transmitter is disposed on one side of the conveyance path. The receiving unit may be arranged on the other side.
Here, the sheet piece detecting means includes a plurality of the transmission units, the plurality of transmission units include first and second transmission units, and the second region is sandwiched on the conveyance path. There are two first regions on both sides in the width direction, and the first transmitter, the second transmitter, and the receiver are emitted from the first transmitter, The ultrasonic wave after passing through the first region and the ultrasonic wave emitted from the second transmitter and passing through the other first region are arranged at positions where the receiver can receive the ultrasonic wave. It is also good.

Here, a period in which the ultrasonic wave emitted from the first transmitter is received by the receiver, and an ultrasonic wave emitted from the second transmitter is received by the receiver. The output timing and output time of the ultrasonic waves by each of the first transmitter and the second transmitter may be determined in advance so that the periods do not overlap.
Here, each of the first and second transmitters outputs ultrasonic waves for the same time Ta at the same time, and the distance La from the first transmitter to the receiver and the reception from the second transmitter. Delay of arrival timing of the ultrasonic wave emitted from the second transmission unit to the reception unit with respect to the ultrasonic wave emitted from the first transmission unit, which is caused by a difference with the distance Lb (> La) to the unit When the time is Tb, the relationship Ta <Tb may be satisfied.

Moreover, after the output of the ultrasonic wave by the first transmitter is finished, the output of the ultrasonic wave from the second transmitter may be started.
Furthermore, in the case of a configuration in which the reception unit simultaneously receives ultrasonic waves emitted from each of the first transmission unit and the second transmission unit, the one first region and the other first region Va is the output voltage of the receiving unit when the sheet piece is not detected at the same time in both Va, the sheet piece is detected in the one first area, and the sheet voltage is detected in the other first area at the same time. The output voltage of the receiving unit in the state B in which no sheet piece is detected is Vb, the sheet piece is not detected in the first first area, and the sheet piece is detected in the other first area at the same time. The output voltage of the receiving unit in the state C is Vc, and the receiving unit in the state D in which the sheet piece is simultaneously detected in both the first region and the other first region. When the output voltage is Vd, there is a relationship of voltage Vd <Vc <Vb <Va or voltage Va <Vb <Vc <Vd, and the sheet piece detecting means sets a threshold th1 between the voltages Va and Vb. The threshold value th2 is set between the voltages Vb and Vc, the threshold value th3 is set between the voltages Vc and Vd, and the above-mentioned one is determined from the magnitude relationship between the output voltage of the receiving unit and the threshold values th1 to th3. The presence or absence of the sheet piece in each of the other first regions may be detected.

  By doing so, it is possible to prevent the peeling of the sheet piece due to the contact between the sheet piece such as a tag attached to the sheet to be conveyed and the conveyance roller, or the occurrence of a jam during sheet conveyance. Become.

1 is a schematic diagram illustrating a configuration of an MFP according to a first embodiment. 1 is a schematic configuration diagram of an image reading apparatus provided in an MFP. FIG. 6 is a plan view schematically showing a positional relationship between a conveyance roller and a tag detection sensor when it is assumed that a document conveyance path of an automatic document conveyance unit is developed in a planar shape. FIG. 6 is a plan view schematically showing an example of the positional relationship between a transport roller, a tag detection sensor, a document to be transported, and a tag attached to the document. (A)-(c) is a figure for demonstrating the generation | occurrence | production mechanism when the sticky note adhering to a document peels off or bends during document conveyance. (A) And (b) is a figure for demonstrating the generation | occurrence | production mechanism when the sticky note adhering to a document bends in Z shape during document conveyance. 2 is a block diagram illustrating a configuration of an overall control unit of the MFP. FIG. 5 is a flowchart showing the contents of document conveyance control. FIG. 10 is a diagram illustrating only a part of a flowchart of document conveyance control including a configuration for rotating each conveyance roller in reverse. It is a figure which shows the structure of the modification which detects the sticky note adhering to the original document using a transmission type optical sensor. 6 is a diagram illustrating a configuration example for detecting a tag attached to a document using an ultrasonic sensor according to Embodiment 2. FIG. 3 is a schematic diagram showing a positional relationship among an ultrasonic sensor, a document, a sticky note attached to the document, and a document transport path. FIG. (A) And (b) is a figure which shows the timing chart of tag detection by the two transmission parts and one receiving part of an ultrasonic sensor. It is a figure which shows the example of the timing chart of tag detection in the case of taking the structure which shifted the output timing of the ultrasonic wave from the two transmission parts of an ultrasonic sensor. It is a figure which shows the example of the timing chart of tag detection in the case of taking another structure. It is a figure which shows the mode of the change of the output voltage of the receiving part of the ultrasonic sensor at the time of taking another structure.

Hereinafter, an embodiment of an image forming apparatus provided with a sheet conveying apparatus according to the present invention will be described with reference to the drawings, taking a multifunctional multifunction peripheral (hereinafter referred to as “MFP (Multi-Function Peripheral)”) as an example. explain.
[Embodiment 1]
<Overall configuration of MFP>
FIG. 1 is a schematic diagram showing a configuration of an MFP according to the present embodiment.

As shown in the figure, the MFP includes an image reading device 1, an image forming unit 2, a paper feeding unit 3, an operation unit 4, and an overall control unit 5.
The image reading apparatus 1 is configured to be able to read an original image by both a sheet-through method that is one of fixed optical systems and a scanner moving method that is one of moving optical systems. Here, the sheet-through method is a method of reading a document being conveyed (moved) at a fixed reading position while the optical system is stationary (fixed). With the scanner movement method, with the document stationary, the mirror that guides the reflected light from the document surface to the reading sensor is moved relative to the document, and the optical path length from the document surface to the reading sensor is always kept constant. This is a reading method.

The present embodiment has a so-called dual scan reading function that can simultaneously read images on the front (front) and back (back) sides of a document in the sheet-through method. Each reading method and function can be selected by the user.
The image reading apparatus 1 includes an image reading unit 10 having a sheet-through glass 13 and a platen glass 16 provided on an upper surface, and an automatic document feeder (ADF) 40 provided above the image reading unit 10. And.

The automatic document transport unit 40 is a document transport device that transports documents placed on the document feed tray 40 a one by one onto the sheet-through glass 13 of the image reading unit 10.
The image reading unit 10 is a fluorescent lamp 11 that is a linear light source on a front surface of a document conveyed on the sheet-through glass 13 by the automatic document conveyance unit 40 or a document placed on the platen glass 16. The reflected light is guided to a CCD (Charge Coupled Device) sensor 12 as a reading sensor through the reduction optical system 15. The CCD sensor 12 generates image data corresponding to the document image by photoelectrically converting the received reflected light of the document, and sends the generated image data to the overall control unit 5.

  An image on the back side of the document is read by a contact image sensor (CIS) 410 provided in the automatic document feeder 40. A contact image sensor (hereinafter referred to as “CIS”) 410 is arranged at a position downstream of the sheet-through glass 13 in the document conveyance direction, and reads an image on the back side of the document while the document passes through the CIS 410. The read image data is sent to the overall control unit 5.

The image forming unit 2 forms an image based on image data output from the CCD sensor 12 of the image reading unit 10, image data output from the CIS 410, and the like. The image forming unit 2 includes an intermediate transfer belt 22 and an image forming unit 23Y. , 23M, 23C, and 23K.
The image forming units 23Y, 23M, 23C, and 23K are arranged along the intermediate transfer belt 22, and are respectively yellow (Y), magenta (M), cyan (C), and black (K) toner images. Form. Since the image forming units 23Y to 23K all have the same configuration, only the image forming unit 23K will be described, and thus other description will be given.

  The image forming unit 23K includes a photosensitive drum 24K, a charger 25K, an exposure device 26K, a developing device 27K, and a primary transfer roller 28K. The outer peripheral surface of the photosensitive drum 24K is uniformly charged by the charger 25K. The exposure device 26K emits a light beam toward the photosensitive drum 24K by a drive signal based on the image data generated by the image reading unit 10, and exposes and scans the surface of the charged photosensitive drum 24K, thereby exposing the photosensitive drum 24K. An electrostatic latent image is formed thereon.

  The electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 24K is developed with toner by the developing device 27K, and the toner image is electrostatically transferred onto the intermediate transfer belt 22 by the primary transfer roller 28K. On the intermediate transfer belt 22, the toner images of Y to K are transferred in a superimposed manner, and a color toner image is formed. When dual scan reading is performed in the sheet-through method, toner image forming operations are sequentially performed on the front and back images of a single document.

  In parallel with the toner image forming operation, the paper feeding unit 3 feeds the paper S one by one from any one of the plurality of paper feeding cassettes 31 accommodated therein, and a secondary transfer roller 21 is provided. Then, it is conveyed to the secondary transfer position. The secondary transfer roller 21 electrostatically transfers the toner image on the intermediate transfer belt 22 onto the paper S. In Dual Scan reading, a toner image representing the front surface of the document transferred onto the intermediate transfer belt 22 is transferred to the first sheet S, and then the document transferred onto the intermediate transfer belt 22 is transferred. A toner image representing the back surface is transferred onto the second sheet S.

The sheet S on which the toner image has been transferred is discharged onto the discharge tray 20a after the toner image is melted and pressed on the sheet S by heating and pressing in the fixing unit 29. Residual toner remaining on the intermediate transfer belt 22 without being transferred onto the paper S is removed by the cleaner 20b.
The operation unit 4 is provided on the front side of the apparatus and is provided at a position where the user can easily operate. The operation unit 4 accepts input such as an instruction to start reading a document from the user, or receives various information based on an instruction from the overall control unit 5. Or a display panel 4a as a touch panel type display unit. The user can check the information displayed on the display panel 4a by visually observing the display panel 4a, for example, a message indicating that a tag is attached to the document as will be described later.

<Configuration of image reading apparatus>
FIG. 2 is a schematic configuration diagram of the image reading apparatus 1.
The sheet-through glass 13 shown in FIG. 1 has a long plate shape that extends long in a direction (main scanning direction) perpendicular to the conveyance direction of the document conveyed by the automatic document conveyance unit 40. The platen glass 16 on which the document is placed is provided downstream of the sheet-through glass 13 in the document transport direction (sub-scanning direction) with an appropriate interval from the sheet-through glass 13.

When the document is read by the sheet through method, the document D placed on the document feed tray 40a of the automatic document transport unit 40 is fed from the document feed tray 40a to the document transport path 401 by the feed roller 41. And conveyed to the separation roller pair 42.
The separation roller pair 42 includes a paper feed roller 420 and a separation roller 422 that are arranged to face each other, and the rotation direction of the opposing portions of the paper feed roller 420 and the separation roller 422 rotates in the opposite direction. The originals D conveyed between the paper feed roller 420 and the separating roller 422 are separated one by one and sent to the intermediate roller pair 43.

The intermediate roller pair 43 includes intermediate rollers 430 and 432 arranged to face each other. The intermediate roller 430 and 432 sandwich and convey the document D and send it to the registration roller pair 44.
The registration roller pair 44 includes registration rollers 440 and 442 that are arranged to face each other, and a single document D to be conveyed is set in a predetermined posture, and the document D is nipped and conveyed at a predetermined timing to be a pre-reading roller. Send to pair 45.

The pre-reading roller pair 45 includes pre-reading rollers 450 and 452 arranged to face each other, and conveys the document D sent from the registration roller pair 44 toward the sheet-through glass 13 for sheet-through. Pass over the surface of the glass 13.
The document D that has passed over the sheet-through glass 13 is conveyed to the roller pair 46 after reading. The post-reading roller pair 46 includes post-reading rollers 460 and 462 arranged to face each other, and sandwich and convey the document D and send it to the CIS 410. The CIS 410 irradiates light on the back surface of the document D that passes directly below (the surface of the document D on the side facing the CIS 410), receives the reflected light, and photoelectrically converts the received reflected light to generate an image. Generate data. The document D that has passed directly under the CIS 410 is conveyed to the pre-discharge roller pair 47.

  The pre-discharge roller pair 47 includes pre-discharge rollers 470 and 472 arranged to face each other, and sandwiches and conveys the document D and sends it to the discharge roller 48. The discharge roller 48 discharges the document D conveyed from the pre-discharge roller pair 47 onto the discharge tray 40b. Although the discharge rollers 48 are not a pair here, they are disposed to face a small-diameter roller (not shown), and both hold and convey the document D.

Each of the above rollers is made of an elastic member such as rubber. For example, one roller of the roller pair may be a high-strength roller made of an elastic member and the other roller made of polyacetal resin.
In the image reading unit 10, when reading a document by the sheet through method, the first slider 18 is moved to a position below the sheet through glass 13 (position in FIG. 2: sheet through position). The front surface of the document D passing over the sheet-through glass 13 is irradiated by the fluorescent lamp 11 of the first slider 18 that is stationary at the sheet-through position.

The light reflected from the front surface of the document D is changed in optical path by the first mirror 15b, the second mirror 15c, and the third mirror 15d, and is connected to the light receiving surface of the CCD sensor 12 by the reduction lens 15e. Imaged.
On the other hand, when the original on the platen glass 16 is read not by the sheet-through method but by the scanner movement method, the automatic document feeder 40 is opened upward and the original is set on the platen glass 16 by the user. The first slider 18 is moved in the direction indicated by the arrow A in FIG. The second slider 19 moves in the same direction at half the moving speed of the first slider 18 so as to follow the movement of the first slider 18, and the distance (optical path length) from the document surface to the CCD sensor 12 is increased. The reflected light of the document is guided to the CCD sensor 12 while being always kept constant.

Among the rollers of the feeding roller 41 to the discharging roller 48, each of the feeding roller 41, the paper feeding roller 420, the separating roller 422, and the discharging roller 48 of the separation roller pair 42 receives the rotational driving force of the transport motor 6.
On the other hand, in each of the intermediate roller pair 43 to the pre-discharge roller pair 47, only the roller in contact with the front surface of the document, for example, the intermediate roller 430, the registration roller 440, and the like receives the rotational driving force of the transport motor 6. . The rollers that are in contact with the back surface of the document, such as the intermediate roller 432 and the registration roller 442, do not receive rotational driving force, and are rotated by the rollers that are in contact with the front surface of the document.

Due to the rotational driving force of the transport motor 6, the rollers of the feeding roller 41 to the discharge roller 48 rotate to transport the document D.
In each of the intermediate roller pair 43 to the pre-discharge roller pair 47, only the rollers on the side in contact with the front surface of the document, for example, the intermediate roller 430 and the registration roller 440 receive the rotational driving force of the transport motor 6, and the back surface of the document The rollers on the side in contact with the sheet, for example, the intermediate roller 432 and the registration roller 442 do not receive the rotational driving force, and are rotated by the roller on the side in contact with the front surface of the document.

  Although not shown in the drawing, a plurality of document jam detection sensors for detecting a jam of the document D being transported are arranged along the document transport path 401 at a predetermined interval. For each of these sensors, based on the detection signal, when the document D being conveyed is not detected even at a predetermined timing, or when the document D is still being detected after the predetermined timing, the document D is detected. Jam is detected.

In a space downstream of the feeding roller 41 in the sheet conveying direction and upstream of the sheet feeding roller 420 in the sheet conveying direction, sheet pieces such as tags and tags attached to the front surface of the document D (hereinafter, “ A sticky note detection sensor 8 for detecting "sticky note") is disposed.
The sticky note detection sensor 8 is a non-contact distance measuring sensor, and controls the signal indicating the distance between the measurement object, here, the front surface of the document D being conveyed (or the tag on the document D). Output to unit 5.

  The overall control unit 5 receives the output signal of the tag detection sensor 8 during conveyance of the document, and measures the distance between the front surface of the document and the tag detection sensor 8 as needed. Then, the overall control unit 5 performs the measurement between the time when the leading edge of one document passes through the detection position P of the tag detection sensor 8 and the time when the trailing edge of the document reaches the detection position P. When it is detected that the distance is shorter than the distance corresponding to the thickness of the tag, it is detected as a tag attached to the document D. Note that the tag detection method is not limited to this.

For example, on the basis of the original distance between the document D and the tag detection sensor 8 when no tag is attached, the measurement distance is shorter than the predetermined value as the thickness of the tag with respect to this reference value. In such a case, it is possible to take a method of detecting sticky note attachment.
Hereinafter, when it is not necessary to particularly distinguish each roller and each roller pair of the feeding roller 41 to the discharge roller 48, these are collectively referred to as a conveyance roller and a conveyance roller pair.

<Positional relationship between the tag detection sensor and the transport roller>
FIG. 3 is a plan view schematically showing the positional relationship between the transport roller and the sticky note detection sensor 8 when it is assumed that the document transport path 401 shown in FIG. In FIG. 3, the conveyance rollers disposed on the opposite side across the document conveyance path 401 are not shown.
As shown in FIG. 3, the direction from the feed roller 41 to the discharge roller 48 is the document transport direction X, and the direction orthogonal to the document transport direction X is the width direction W of the document D. A line CL indicating the center in the width direction W of the document conveyance path 401 becomes the center line of the document conveyance path 401, and the document D is in a state where the center in the width direction of the document D coincides with the center line CL in the width direction W. The set position of the document D in the width direction W on the document feed tray 40a is determined in advance so as to be conveyed.

Two feed rollers 41 are arranged at intervals along the width direction W, and the feed roller 420 is configured such that one roller body 421 is provided on the rotation shaft 423. This roller body is a small roller whose length in the width direction W (roller width) is sufficiently shorter than the length in the width direction of the document conveyance path 401.
The intermediate roller 430 is provided with three roller bodies 431 at intervals along the width direction W on the rotation shaft 433, and the registration roller 440 is spaced at intervals along the width direction W with respect to the rotation shaft 443. Three roller main bodies 441 are provided.

The pre-reading roller 450 has four roller bodies 451 provided on the rotation shaft 453 at intervals along the width direction W, and the post-reading roller 460 is spaced on the rotation shaft 463 along the width direction W. Four roller main bodies 461 are provided.
The pre-discharge roller 470 includes four roller main bodies 471 spaced along the width direction W on the rotation shaft 473, and the discharge roller 480 is spaced along the width direction W on the rotation shaft 483. The four roller bodies 481 are provided.

Each of the rotation shafts 433 to 483 is rotatably supported by support members 491 and 492 disposed on one end side and the other end side in the width direction W, and is rotationally driven by the driving force of the transport motor 6. The same applies to the respective rotation shafts (not shown) of the feeding roller 41 and the separation roller 422.
Each transport roller may rotate at the same time during transport of the document, or a predetermined operation such as when one transport roller rotates and another transport roller temporarily stops at a predetermined timing. Executed. For example, an electromagnetic clutch (not shown) provided in the middle of the drive path from the conveyance motor 6 to the rotation shaft for each rotation shaft provided with each conveyance roller is switched between rotation and stop of the specific conveyance roller. This is done by turning on and off.

A plurality of transport rollers having the same name are arranged at symmetrical positions with the center line CL interposed therebetween.
Further, roller bodies 421, 431, and 441 positioned on the center line CL are arranged in a line along the document transport direction X. This roller row is referred to as a roller row 77c.

Similarly, the roller bodies 451, 461, 471, 481 located on the outermost sides on one end side and the other end side in the width direction W are also arranged in a line along the document transport direction X. These roller rows are referred to as roller rows 77a and 77e.
Further, apart from the above, two roller rows composed of roller bodies 431, 441, 451, 461, 471, 481 arranged along the document conveying direction X are arranged so as to be arranged at intervals in the width direction W. Yes. These roller rows are referred to as roller rows 77b and 77d.

  Among the six roller bodies 431 to 481 belonging to the roller row 77b, when at least two roller bodies have different width direction lengths (roller width Wr), at least two roller bodies are shifted in the width direction W even if all are the same. Are arranged in the same direction, or when all are the same, the minimum area 9b in the width direction W (area between two broken lines) including all roller bodies is referred to as a roller installation area on the document conveyance path 401.

The roller installation area 9b has an edge on one end side in the width direction of the roller body 431 closest to one end side in the width direction W among the six roller bodies whose length 7b in the width direction exists in the area 9b. This is a region equal to the length in the width direction W from 434 to the edge 484 on the other end side in the width direction of the roller body 481 closest to the other end side in the width direction W.
Similarly, the roller installation area for the roller array 77a is referred to as 9a, the roller installation area for the roller array 77c is referred to as 9c, the roller installation area for the roller array 77d is referred to as 9d, and the roller installation area for the roller array 77e is referred to as 9e.

  Each of the roller installation areas 9a to 9e is a first area in which any roller body exists at any position between the upstream side and the downstream side along the document transport direction X on the document transport path 401. I can say that. On the other hand, the regions 93 a to 93 e other than the roller installation regions 9 a to 9 e on the document conveyance path 401 can be said to be second regions where no roller body exists at any position along the document conveyance direction X.

  In the present embodiment, in each of the plurality of regions 9a to 9e in the plurality of transport rollers from the paper feed roller 420 to the discharge roller 48 along the document transport direction X, the document transport direction X is included in the region. It is the structure arrange | positioned so that two or more roller main bodies may be located in a line. FIG. 3 shows a configuration example in which a plurality of roller bodies are arranged in a line along the document transport direction X in one area. However, the present invention is not limited to this. There may be a configuration in which only one roller body is located.

A total of five sticky note detection sensors 8 are arranged, and in FIG. 3, reference numerals 8a to 8e are given to distinguish each of them. Each of the tag detection sensors 8a to 8e is arranged above the document conveyance path 401, arranged in a line at a predetermined interval along the width direction W at a position where the distance from the document conveyance path 401 becomes equal. Yes.
The document detection position P on the document conveyance path 401 by the sticky note detection sensor 8a is the document conveyance direction X more than the roller main body 451 located at the most upstream of the document conveyance direction X among the four roller bodies belonging to the roller row 77a. Located on the upstream side. The length (detection width) and the position (width direction position) in the width direction W at the detection position P are equal to the width direction length 7a and the width direction position of the roller installation region 9a.

  Similarly, the other sticky note detection sensors 8b to 8e also have their respective detection positions P on the document transport path 401 at the most upstream position in the document transport direction X among the plurality of roller bodies belonging to the corresponding roller row. The detected width and the width direction position are equal to the width direction lengths 7b to 7e and the width direction positions of the corresponding roller installation regions 9b to 9e.

For each of the tag detection sensors 8a to 8e, the document (or the tag on the document) can be detected only within the respective ranges of the detection widths 7a to 7e on the detection position P. For example, the detection width 7a And a second region 93a (region in which no roller main body exists at any position along the document transport direction X) is a non-detection region (undetectable).
The reason for this positional relationship is that when it is assumed that the document D to which the sticky note is attached is transported, whether or not the sticky note is in contact with any of the transport rollers is predicted before reaching the contact state. It is to do.

For example, as shown in FIG. 4, it is assumed that a document D to which three strip-shaped sticky notes 81 to 83 are attached is conveyed. The sticky note 81 does not overlap any detection width (roller installation area) in the width direction W. However, for the sticky notes 82 and 83, at least a part of the width direction W has detection widths 7b and 7d (roller installation areas 9b and 9d). ).
Accordingly, during the conveyance of the document D, the sticky note 81 does not touch any roller body, but the sticky notes 82 and 83 touch the roller body 431 existing within the detection widths 7b and 7d. Since a sticky note touches a roller body is equivalent to a sticky note touching a transport roller having the roller body as a component, hereinafter, the sticky note touches the transport roller.

If a sticky note adhering to the original D is in contact with any of the transport rollers while the original is being transported, as described in the section “Problems to be Solved by the Invention” above, the sticky note is peeled off, bent, or peeled off. Document jam is likely to occur.
The mechanism of occurrence of peeling and bending of the sticky note will be specifically described with reference to FIGS. FIG. 5A is a diagram illustrating a state in which the document D to which the sticky note 82 is attached is conveyed toward the intermediate roller pair 43.

As shown in the drawing, guide members 436 and 437 are arranged on the upstream side in the document transport direction X with respect to the intermediate roller pair 43 with a space in the vertical direction, and on the downstream side in the document transport direction X, Guide members 438 and 439 are arranged at intervals in the vertical direction.
The guide members 436 to 439 guide the conveyance of the document D, and the conveyance path of the document D conveyed by the guidance of the guide members 436 to 439 becomes the document conveyance path 401. The guide members 436 to 439 are disposed with a gap 62d with respect to the intermediate rollers 430 and 432 so as not to contact the peripheral surfaces of the intermediate rollers 430 and 432.

The sticky note 82 attached to the document D is composed of a portion 82a having an adhesive surface to be attached to the document and a portion of the other non-adhesive surface. In FIG. A state is shown in which the document D is attached to the front surface Da of the document D in a state of being located on the upstream side in the document transport direction X with respect to the portion.
When conveyance of the original D proceeds and the sticky note 82 attached to the original D passes the intermediate roller pair 43, as shown in FIG. 5B, the tip 82b of the non-adhesive portion of the sticky note 82 is on the driving side. The intermediate roller 430 may be swung up by the driving force of the intermediate roller 430, may be lifted from the front surface Da of the document D, and may enter the gap 62d between the intermediate roller 430 and the guide member 438.

When the conveyance of the document D further proceeds in a state where the tip 82b of the sticky note 82 enters the gap 62d between the intermediate roller 430 and the guide member 438, as shown in FIG. Bending occurs between the portion 82a having the adhesive surface.
At this time, when the portion 82 a having the adhesive surface of the sticky note 82 is peeled off from the original D, the front end 82 b of the sticky note 82 enters the gap 62 d between the intermediate roller 430 and the guide member 438 after the original D passes through the intermediate roller pair 43. In this state, the sticky note 82 may remain on the document conveyance path 401. If the sticky note 82 remains in the document conveyance path 401, jamming is likely to occur in the document D due to a collision with another document D conveyed thereafter. Even if the sticky note 82 is not peeled off from the document D, the sticky note 82 is folded in two.

FIG. 6A shows that the portion 82a having the adhesive surface of the sticky note 82 is attached to the front surface Da of the document D in a state where the portion 82a is located downstream of the non-adhesive surface portion in the document transport direction X. An example is shown.
When the conveyance of the document D proceeds and the portion 82a having the adhesive surface of the sticky note 82 passes through the intermediate roller 430 on the driving side, the intermediate roller 430 contacts the non-adhesive surface portion of the sticky note 82 as shown in FIG. To do. By this contact, the conveying force by the driving-side intermediate roller 430 acts on the non-adhesive surface portion of the sticky note 82, but the non-adhesive surface portion of the sticky note 82 is not adhered to the front surface Da of the document D. The conveying force is hardly transmitted to the document D.

Therefore, at the moment when the driving-side intermediate roller 430 comes into contact with the non-adhesive surface portion of the sticky note 82, the non-adhesive surface portion of the sticky note 82 runs on the front surface Da of the original D along the original transport direction X. It is transported to slide. Thus, two portions of the sticky note 82 between the portion 82a having the adhesive surface and the portion in contact with the peripheral surface of the intermediate roller 430 are folded.
The operation of folding the sticky note 82 in two is continued until the entire sticky note 82 passes through the intermediate roller 430, during which the two folded portions of the sticky note 82 have a gap 62 d between the intermediate roller 430 and the guide member 438. Get in.

When the folded portion of the sticky note 82 enters the gap 62d and the document D is transported while being caught by the guide member 438, the portion 82a having the adhesive surface of the sticky note 82 is peeled off from the document D, and the document transport path 401 It is easy to occur that the sticky note 82 after being folded into two remains.
The occurrence of the folding or peeling of the sticky note 82 can occur in the same manner also in the separation roller pair 42, the registration roller pair 44, etc. other than the intermediate roller pair 43. Note that the feeding roller 41 is disposed immediately above the document feed tray 40a and remains on the document feed tray 40a even if the sticky note 82 is peeled off. It is unlikely that a jam occurs on the conveyance path 401.

  Therefore, in the present embodiment, detection signals of sticky note detection sensors 8a to 8e provided corresponding to the arrangement positions of the respective conveying rollers in the width direction W after the conveyance of the original D is started for each original D. Monitor from time to time. When a sticky note adhering to the original D is detected from the start of transport of the original D, it is predicted that the sticky note will come into contact with the transport roller if the transport is further continued. Therefore, the conveyance of the document D is immediately interrupted. This prevents the sticky notes from being peeled off and the original jam from occurring.

  On the other hand, if no sticky note is detected by the sticky note detection sensors 8a to 8e while the document D is being transported, it is presumed that the sticky note in contact with the transport roller is not attached to the document D, and transport of the document D is continued to the end. . The fact that no sticky note is detected is equivalent to the fact that the region from one end to the other end in the width direction W of the sticky note does not overlap at all in the width direction W with any of the roller installation regions 9a to 9e.

That is, even if a tag is attached to a position other than the roller installation area (detection width) on the front surface of the document D, the tag does not contact any of the transport rollers during transport of the document D. The sticky note does not peel off or bend due to the sticky note coming into contact with the transport roller.
This is because if the sticky note detection sensors 8a to 8e as sheet piece detecting means are arranged only in positions corresponding to the roller installation areas 7a to 7e in the width direction W on the original transport path 401, the sticky notes come into contact with the transport rollers. This means that it is possible to prevent sticky notes from being peeled off or bent. Therefore, the number of sticky note detection sensors can be reduced and the cost merit is great compared to a configuration in which the sticky note detection sensors are arranged at positions where no transport roller exists.

Further, even if a sticky note is attached to the document D, the document transport is continued unless it comes into contact with any of the transport rollers. Therefore, when the tag is attached to the document D, the document D is not uniformly transported. Compared to the above, the transportability of the document D can be improved.
<Configuration of overall control unit>
FIG. 7 is a block diagram showing the configuration of the overall control unit 5.

As shown in the figure, the overall control unit 5 includes a CPU 51, a ROM 52, a RAM 53, and a document conveyance control unit 54, which can communicate data with each other.
The CPU 51 reads a program for executing a printing operation and the like stored in the ROM 52, and comprehensively controls the operations of the image reading device 1, the image forming unit 2, the paper feeding unit 3, and the like, so that smooth printing is performed. Etc. are realized. Further, the CPU 51 receives an operation input by the user from the operation unit 4, for example, a document reading start instruction, and displays various messages on the display panel 4a. The RAM 53 serves as a work area for the CPU 51.

  When the document conveyance control unit 54 receives an instruction from the user to start document reading (document D conveyance start) from the operation unit 4, the document conveyance control unit 54 controls rotation of the conveyance motor 6 of the automatic document conveyance unit 40 to supply the documents one by one. Transport paper. At this time, for each original document, after the start of conveyance of the original document, the output signals of the tag detection sensors 8a to 8e are received at any time to determine whether to continue or interrupt the original document conveyance. The rotation of the transport motor 6 is stopped. As a result, the rotation of all the conveyance rollers is stopped, and the conveyance of the original is stopped.

<Contents of document transport control>
FIG. 8 is a flowchart showing the contents of the document conveyance control. This control is executed by the document conveyance control unit 54 and is started by an instruction to start document conveyance from the CPU 51.
As shown in the figure, the conveyance of the document is started (step S1). As a result, the uppermost document D among the one document D or the plurality of documents D placed on the document feed tray 40a is fed out by the feed roller 41 one by one. The fed document D is transported along the document transport direction X from the separation roller pair 42 to the discharge roller 48 and discharged onto the discharge tray 40b unless the transport is interrupted due to the attachment of the sticky note 82.

For each document D, after the conveyance of the document D is started, it is determined whether or not the tag 82 attached to the document D is detected (step S2). This determination is performed by monitoring whether the output signals of the tag detection sensors 8a to 8e are received, for example, every time they are received at regular intervals (several milliseconds, etc.), it is determined whether or not the received output signal indicates the detection of the tag 82. Is done.
If it is determined that the tag 82 is not detected (“No” in step S2), it is determined whether the document D to be conveyed remains on the document feed tray 40a (step S3). If it is determined that the document D remains (“Yes” in step S3), the process returns to step S2 to determine whether or not a tag is detected. If the sticky note 82 is not detected (“No” in step S2) and the document D to be conveyed still remains (“Yes” in step S3), the process returns to step S2.

  If the sticky note 82 is not detected before the conveyance of all the documents D to be conveyed is completed, the processes in steps S2 and S3 are repeated. When it is determined that all the documents D to be transported have been transported and no documents remain ("No" in step S3), the transport motor 6 is stopped after the last document D is ejected to the ejection tray 40b. Thus, the document conveyance is finished (step S4), and the document conveyance control is terminated.

  On the other hand, when it is determined that the tag is detected (“Yes” in step S2), the conveyance of the document D to which the detected tag 82 is attached is interrupted (step S5). The conveyance of the document D is interrupted by stopping the rotation of the conveyance motor 6. Judgment of tag detection is equivalent to predicting that the tag will come into contact with any of the transport rollers by continuing the subsequent document transport. Further, the interruption of the conveyance of the document D is equivalent to the control for stopping the rotation of each conveyance roller.

Then, the user is notified of the detection of the sticky note 82 and its attachment position (step S6). This notification to the user includes a message that the document D is not conveyed because the tag 82 is attached to the document D being conveyed on the display panel 4a of the operation unit 4, and a tag 82 on the document D. This is done by displaying a message indicating the attachment position of.
The attachment position of the sticky note 82 can be indicated by an arrangement position in the width direction W of the sensor that detects the sticky note 82 among the sticky note detection sensors 8a to 8e. For example, the sticky note detection sensors 8a to 8e are arranged in five levels in the width direction W. Specifically, the sticky note 82 is detected by dividing the position in the depth direction of the device into the back side, back side, center, front side, and front side most. A message indicating the arrangement position corresponding to the sensor can be displayed. More specifically, if the sensor that detects the sticky note 82 is 8a, a message indicating that the sticky note is attached to the most rear side of the document D is displayed, and if the sensor that detects the sticky note 82 is 8e. A message indicating that a sticky note is attached to the most front side of the document D can be displayed.

In addition, the attachment position of the sticky note 82 on the document D is not limited to the position in the width direction W, but may be an attachment position in the document transport direction X instead. This adhesion position can be determined as follows.
A timer (not shown) measures the time Tx from the start of conveyance of the document D to the detection of the tag 82. The distance Xa (= Tx × Vx) on the document conveyance path 401 from the reference position to the position of the leading edge of the document D in the conveyance direction at the time of sticky note detection is based on the position of the leading edge of the document D in the conveyance direction at the start of conveyance. Ask for. Here, Vx is a conveyance speed of the document D and is determined in advance.

  The obtained distance Xa is the distance Xb on the document conveyance path 401 from the leading edge of the document to the detection position P by the tag detection sensor 8 and the distance Xc (specified value) on the document conveyance path 401 from the detection position P to the reference position. ) Is equal to the sum of Therefore, if the distance Xb (= Xa−Xc) is obtained, the attachment position of the sticky note 82 in the document transport direction X from the front end of the document on the document D can be detected.

If the positions in both the width direction W and the document conveyance direction X are detected, the attachment position of the sticky note 82 on the document D can be indicated to the user in a two-dimensional coordinate position.
In addition, it is not restricted to a message display, For example, an illustration display can also be used. It is conceivable that the document D is indicated by a rectangular illustration, and the illustration of the tag 82 is displayed in the rectangular region at the position corresponding to the sensor that detected the tag 82 (or the two-dimensional coordinate position).

In addition, the configuration is not limited to the above as long as it can notify the user who has instructed the start of document conveyance as predetermined information that the document is not conveyed due to attachment of a tag. For example, the information can be output as a sound from a speaker, or can be transmitted to a terminal such as a personal computer used by the user via a network or the like.
By this notification, the user can know that the interruption of the document conveyance is caused by the sticky note 82 and the attachment position of the sticky note 82. Then, the user once takes out the document D stopped on the document transport path 401 from the document transport path 401 by opening and closing the exterior cover of the automatic document transport unit 40. Then, after the sticky note 82 is removed from the taken out document D, the document D can be reset again on the document feed tray 40a, and then the operation unit 4 can be instructed to resume document conveyance.

The user can also instruct the operation unit 4 to stop the document conveyance. This can be realized by providing the operation unit 4 with keys and buttons for accepting instructions for resuming and stopping document conveyance.
If it is determined that the user has received an instruction to resume document conveyance (“Yes” in step S7), document conveyance is resumed (step S8), and the process proceeds to step S3. The resumption of the document conveyance is started by the feeding operation of the uppermost document D by the feeding roller 41, similarly to the start of document feeding.

On the other hand, when it is determined that the user has received an instruction to cancel the document conveyance (“No” in step S7, “Yes” in S9), the document D is displayed when the document D is stopped on the document conveyance path 401. A message to remove is displayed on the display panel 4a of the operation unit 4 (step S10), and the document transport control is terminated.
In this case, when it is detected that the stopped document D is removed from the document conveyance path 401 by the user, the document conveyance interruption is reset, and thereafter, document conveyance control for another document can be executed. become. The detection that the document D has been removed is performed by monitoring the output signal of the jam detection sensor and determining that the stopped document D is no longer detected by any jam detection sensor. Can do.

  As described above, in the present embodiment, the sticky note 82 attached to the document D comes into contact with any one of the transport rollers after the transport of the document D is continued for each document D. Is detected, the conveyance of the document D is interrupted. As a result, the sticky note 82 attached to the original D can be prevented from being peeled off or bent and the occurrence of the original jam due to contact with the transport roller, thereby improving the transportability of the original.

  In addition, although the above demonstrated the structural example provided with the common conveyance motor 6 as a drive source which rotationally drives different conveyance rollers, such as the intermediate | middle roller pair 43 and the registration roller pair 44, it is not restricted to this. A separate transport motor is assigned to each of the different transport rollers, such as a first transport motor that rotationally drives the intermediate roller pair 43 and a second transport motor that rotationally drives the pair of registration rollers 44, and each transport motor is rotated individually. It is also possible to separately control the rotation of different transport rollers by switching between and stop.

Further, in the above, the conveyance of the document D is interrupted by detecting the sticky note 82 (“Yes” in step S2, S5), and when an instruction to resume conveyance is received after the user resets the document (“Yes” in step S7). However, the conveyance of the document D is resumed, but the present invention is not limited to this.
For example, each transport roller can rotate (reverse) in the direction opposite to the rotation direction (forward rotation) when transporting the document D, and the document D can be transported in the direction opposite to the original transport direction by this reverse rotation. If it is a simple structure, after the conveyance of the document D is interrupted (step S5), the respective conveyance rollers are rotated in the reverse direction to convey the document D stopped by the conveyance interruption in the direction opposite to the document conveyance direction X. It is also possible to adopt a configuration in which the operation of returning toward the document feed tray 40a is automatically performed.

FIG. 9 is a diagram showing only a portion different from the flowchart shown in FIG. 8 with respect to the flowchart of the document conveyance control including a configuration in which each conveyance roller is reversely rotated, and step S21 is performed between steps S5 and S6. Indicates that it will be executed. Except for executing step S21, the same processing as the flowchart shown in FIG. 8 is executed.
When the conveyance of the document D is interrupted (step S5), the respective transport rollers are rotated in reverse at a predetermined speed to return the document D to the document feed tray 40a (step S21), and the process proceeds to step S6.

As a result, the document D for which the conveyance has been interrupted is returned to the document feed tray 40a, so that the user removes the document D stopped on the document conveyance path 401 with his / her hand by opening / closing the outer cover or the like. There is no need to perform an operation, and the user operability can be improved.
Note that the predetermined speed can be determined in advance. In addition, if the time required from the start of feeding of the document D to the stop due to the interruption of conveyance is measured, by multiplying the measurement time by a prescribed document conveyance speed, the time from the start of feeding of the document D to the stop is measured. The conveyance distance can be obtained. By setting the reverse rotation time of each transport roller so that the document D is transported in the reverse direction by an amount corresponding to this transport distance or by adding an error thereto, the document D is moved from its stop position to the document D. It is possible to return to the paper feed tray 40a.

In the above description, a configuration example using a distance sensor as the tag detection sensor 8 has been described. However, the detection sensor is not limited to the distance sensor as long as it can detect the presence or absence of a tag attached to the document D. For example, a reflective or transmissive optical sensor may be used to detect the presence or absence of sticky notes from the amount of change in reflected light from the document D or transmitted light from the document D.
When a transmissive optical sensor is used, for example, as shown in FIG. 10, a configuration in which the light emitting unit 8f is arranged on the upper side across the document conveyance path 401 and the light receiving unit 8g is arranged on the lower side can be adopted. The light receiving unit 8g receives the light emitted from the light emitting unit 8f and outputs a voltage having a magnitude corresponding to the amount of light received.

  In the case of adopting this configuration, the following control method can be used to detect a tag. That is, when the light emitted from the light emitting unit 8f is transmitted through a portion of the document D where the tag 82 is not attached as a reference light amount, the portion to which the tag 82 is attached (that is, the document 82) The amount of light after transmission through both D and the tag 82) is smaller than the reference light amount because the amount of attenuation at the time of transmission increases as much as the tag 82 exists.

  Therefore, it is assumed that the output voltage of the light receiving unit 8g is monitored while the document D is being conveyed, and the output voltage of the light receiving unit 8g is lowered by the attachment of the sticky note 82 to the reference value Vr when the reference light amount is received. If it does not drop to the predetermined value Vq, it can be detected that the sticky note 82 is not attached, and if it falls to the predetermined value Vq, the attachment of the sticky note 82 can be detected. The arrangement positions of the light emitting unit 8f and the light receiving unit 8g are opposite to the above, that is, the light emitting unit 8f is arranged on the lower side across the document conveyance path 401, and the light receiving unit 8g is arranged on the upper side. it can.

If the configuration using this transmissive optical sensor is adopted, even if the sticky note 82 is attached not only to the front surface side of the document D but also to the back surface side of the document D as shown in FIG. Can be detected. The fact that the tag 82 attached to the back side of the document D can also be detected is the same in the configuration using the ultrasonic sensor described below.
[Embodiment 2]
In the first embodiment, the configuration example using the distance measuring sensor as the tag detection sensor 8 has been described. However, in the second embodiment, an ultrasonic sensor is used, which is different from the first embodiment. .

  In the first embodiment, the detection width is five rows (7a to 7b). However, in the second embodiment, the detection width is four rows, and this is also different. Specifically, the roller installation area 9c in the first embodiment does not exist, and the roller main bodies 431 and 441 that existed in the roller installation area 9c are not arranged in the second embodiment. Further, the separation roller pair 42 existing in the roller installation area 9c is arranged in each of the roller installation areas 9b and 9d. Hereinafter, in order to avoid duplication of explanation, explanation of the same contents as those in Embodiment 1 is omitted, and the same constituent elements are denoted by the same reference numerals.

FIG. 11 is a diagram illustrating a configuration example in which the ultrasonic sensor 90 according to the present embodiment is disposed in a space between the feeding roller 41 and the separation roller pair 42.
As shown in the figure, the ultrasonic sensor 90 receives ultrasonic waves that have passed through the document D among the ultrasonic waves emitted from the transmitter 91 and the transmitter 91 that emits ultrasonic waves, in this case, infrared rays. The receiving unit 92 outputs an electric signal according to the intensity of the received ultrasonic wave, here, a voltage. The number of transmitting units 91 and receiving units 92 is not the same in the present embodiment, and two receiving units 92 are arranged for three transmitting units 91.

FIG. 12 is a view of the ultrasonic sensor 90 as viewed from the direction indicated by the arrow B shown in FIG. 11. The ultrasonic sensor 90 is conveyed through the three transmission units 91 a to 91 c, the two reception units 92 a and 92 b, and the document conveyance path 401. 6 is a schematic diagram showing a positional relationship between a document D to be detected and the detection widths 70 a to 70 d of sticky notes by the ultrasonic sensor 90.
As shown in FIG. 12, three transmitters 91a, 91b, 91c are arranged on the upper side of the document conveyance path 401 with a space along the width direction W, and two receivers 92a are arranged on the lower side. , 92b are arranged at intervals along the width direction W.

  The transmission unit 91b is disposed at the same position in the width direction W as the center line CL indicating the center in the width direction of the document conveyance path 401, and the transmission units 91a and 91c are symmetrically positioned in the width direction W across the transmission unit 91b. Has been placed. The transmitter 91b disposed at the center in the width direction has a characteristic in which the directional angle of the emitted ultrasonic wave is wide and the emitted ultrasonic wave travels in a wide angle state. In FIG. 12, the state in which the ultrasonic wave emitted from the transmitter 91b spreads and travels is schematically represented by a plurality of arrows (broken lines). Here, transmitters 91a and 91c arranged on the left and right sides in the width direction have narrower directivity angles than the transmitter 91b.

The receiving unit 92a is disposed at a position facing the transmitting unit 91a with the document conveying path 401 interposed therebetween, and the receiving unit 92b is disposed at a position facing the transmitting unit 91c with the document conveying path 401 interposed therebetween. On the other hand, no receiving unit is disposed at a position facing the transmitting unit 91b.
The detection widths 70a, 70b, 70c, 70d of the sticky notes by the ultrasonic sensor 90 correspond to the detection widths 7a, 7b, 7d, 7e shown in FIG. The positional relationship is arranged in In other words, in the width direction W, no roller body exists at positions other than the detection widths 70a to 70d.

The detection width 70a is a detection width by a pair of the transmission unit 91a and the reception unit 92a, the detection width 70b is a detection width by a pair of the transmission unit 91b and the reception unit 92a, and the detection width 70c is a transmission unit 91b. The detection width 70d is a detection width based on the combination of the transmission unit 91c and the reception unit 92b.
In the present embodiment, the arrangement position of each unit, the directivity angle of the ultrasonic wave, the size of the receiving unit, and the like are determined in advance so that the transmitting units 91a to 91c and the receiving units 92a and 92b satisfy the following conditions.

  That is, only the ultrasonic wave that has passed through the detection width 70a among the ultrasonic waves emitted from the transmitting unit 91a can be received by the receiving unit 92a. In other words, the ultrasonic wave that has passed through the region other than the detection width 70a in the width direction W cannot be received by the receiving unit 92a. This also applies to the transmitter 91c, and only the ultrasonic waves that have passed through the detection width 70d among the ultrasonic waves emitted from the transmitter 91c can be received by the receiver 92b.

Further, with respect to the transmitting unit 91b, only the ultrasonic wave that has passed through the detection width 70b can be received by the receiving unit 92a and only the ultrasonic wave that has passed through the detection width 70c among the ultrasonic waves emitted from the transmitting unit 91b. The reception unit 92b can receive the wave.
In the figure, the ultrasonic wave that has been transmitted from the transmitter 91b is transmitted in the course of the path so that the ultrasonic wave after passing through both outer sides of the detection width 70b in the width direction W does not reach the receiver 92a. A configuration example is shown in which shielding members 89a and 89b for shielding are arranged at intervals of 89c in the vertical direction. Of the ultrasonic waves emitted from the transmitter 91b, only the ultrasonic waves after passing through the detection width 70b can be received by the receiver 92a through the interval 89c between the shielding members 89a and 89b. Similar shielding members 89a and 89b are also provided for the receiving section 92b.

  Further, instead of the configuration in which the shielding members 89a and 89b are provided, for example, the ultrasonic wave detection surface of the receiving unit 92a is set to the ultrasonic wave after passing through both outer sides of the detection width 70b of the ultrasonic wave emitted from the transmitting unit 91b. It is also possible to adopt a configuration in which the size is limited so that the ultrasonic wave after passing through the detection width 70b can be received. The same applies to the receiving unit 92b. Any structure that satisfies the above conditions may be used, and, apart from the above, for example, an ultrasonic wave that has passed through the detection width (such as 70a) among the ultrasonic waves that have spread and then emitted from the transmitting unit (such as 91a). It is also possible to adopt a configuration in which only the light is reflected by the reflecting member and then guided to the receiving unit 92a.

When the document D is being conveyed, of the ultrasonic waves emitted from the transmitter 91a, the document D is transmitted through the detection width 70a, or both the document D and the tag 81 are attached when the tag 81 is attached. The transmitted signal is received by the receiving unit 92a, and a voltage corresponding to the intensity (reception amount) of the received ultrasonic wave is output from the receiving unit 92a.
The amount of attenuation when ultrasonic waves pass through the document D changes depending on whether or not the sticky note 81 is attached, and the output voltage of the receiving unit 92a also changes. Accordingly, the amount of change is obtained in advance by experiments or the like, the output voltage of the receiving unit 92a is monitored during document conveyance, and the change in the output voltage due to the adhesion of the sticky note 81 is detected. Thus, it is possible to detect the sticky note 81 having at least a part within the detection width 70. The same applies to the other detection widths 70b to 70d.

In the example of FIG. 12, in the width direction W, a sticky note 81 existing in the detection width 70a and a sticky note 83 existing in the detection width 70b are detected, and a sticky note 82 that does not exist in any detection width is not detected.
In the present embodiment, since the two transmitting units 91a and 91b share one receiving unit 92a, it is not possible to simultaneously detect a tag in each of the detection widths 70a and 70b.

Therefore, the detection of the sticky note in the detection width 70a and the detection of the sticky note in the detection width 70b are performed at different times.
FIG. 13 is a diagram illustrating a timing chart of tag detection by the transmission units 91a and 91b and the reception unit 92a. FIG. 13A illustrates a case where a tag on the document D is not detected, and FIG. A case where sticky notes 81 and 83 on the document D are detected is shown.

  As shown to Fig.13 (a), the transmission parts 91a and 91b emit an ultrasonic wave (pulse wave) simultaneously from time t1 to t2 (ON). The frequency and amplitude of the pulse wave emitted from each of the transmitters 91a and 91b are the same (the power is the same). The frequency is a predetermined value, for example, about 300 KHz. One ultrasonic output time (between time points t1 and t2) is referred to as a pulse output time Ta, and the pulse output time Ta is determined in advance as a predetermined length of time.

The ultrasonic wave emitted from the transmitter 91a passes through the document D (not attached with a tag), reaches the receiver 92a, and is detected by the receiver 92a (time points t3 to t4). Here, Va is the output voltage of the receiving unit 92a when the tag is not attached, and V0 is the output voltage when the receiving unit 92a is not receiving ultrasonic waves.
On the other hand, the ultrasonic wave emitted from the transmission unit 91b passes through the document D (with no tag attached), reaches the reception unit 92a at time t5, and is detected by the reception unit 92a (time t5 to t6). The output voltage of the receiving unit 92a at this time is Vb (<Va).

The transmitters 91a and 91b start outputting ultrasonic waves at the same time (time point t1), but the arrival timing of the ultrasonic waves from the transmitter unit 91b to the receiver unit 92a (time point t5) is more from the transmitter unit 91a. It is later than the arrival timing (time point t3) of the ultrasonic wave to the receiving unit 92a.
This is because the sound speeds of the ultrasonic waves emitted from the transmitters 91a and 91b are the same, whereas the distance La from the transmitter 91b to the receiver 92a is greater than the distance La from the transmitter 91a to the receiver 92a. This is because the arrival timing is different by the difference of the distance because it is longer. The delay time of the arrival timing (time t5) of the ultrasonic wave emitted from the transmission unit 91b with respect to the arrival timing (time point t3) of the ultrasonic wave emitted from the transmission unit 91a is denoted by Tb. To do.

  If the relationship of pulse output time Ta <delay time Tb is satisfied, in one receiving unit 92a, firstly, an ultrasonic wave emitted from transmitting unit 91a is detected between time points t3 and t4, and thereafter, from transmitting unit 91b. The emitted ultrasonic wave can be detected between time points t5 and t6. That is, the detection of the presence / absence of the sticky note 81 in the detection width 70a by the ultrasonic wave emitted from the transmitter 91a and the detection of the presence / absence of the sticky note 83 in the detection width 70b by the ultrasonic wave emitted from the transmitter 91b are shifted in time. Can be performed (at different times).

Further, the output voltage Vb of the receiving unit 92a is smaller than the output voltage Va of the receiving unit 92a when an ultrasonic wave is emitted from the transmitting unit 91a. This is due to the following reason.
That is, both the ultrasonic wave emitted from the transmission unit 91a and the ultrasonic wave emitted from the transmission unit 91b pass through the document D having the same thickness when no sticky note is attached to the document D. It will be almost the same. On the other hand, the ultrasonic wave attenuates as the propagation distance becomes longer, and there is a relationship of distance La <Lb as described above. For this reason, the output voltage Vb of the receiving unit 92a is smaller than the output voltage Va by an attenuation amount corresponding to the difference between the distances La and Lb. In the example of FIG. 13A, the output voltage of the receiving unit 92a has a relationship of V0 <Vb <Va.

  After the output of the ultrasonic wave from the transmitter 91b ends (time t6), the output of the ultrasonic wave from the transmitter 91a starts when the time t7 is reached. While the document D is being conveyed, the operation of outputting ultrasonic waves from the transmitting units 91a and 91b and detecting ultrasonic waves by the receiving unit 92a between time points t1 and t7 is repeatedly executed at regular time intervals. This fixed time corresponds to one sticky note detection time (one cycle), and can be, for example, about 10 ms (milliseconds).

On the other hand, when the tag 81 is attached to the document D, the ultrasonic wave emitted from the transmitting unit 91a is detected by the receiving unit 92a after passing through both the document D and the tag 81. Due to the attenuation, the output voltage of the receiving unit 92a becomes Va1 (<Va) as shown in FIG.
That is, since a difference occurs in the output voltage of the receiving unit 92a depending on the presence or absence of the sticky note 81 on the document D, if a predetermined voltage that is smaller than the output voltage Va and larger than the output voltage Va1 is determined in advance as the threshold th1. The presence / absence of the sticky note 81 can be detected by determining the magnitude relationship between the output voltage of the receiving unit 92a and the threshold value th1 between time points t3 and t4.

The same applies to the case where the ultrasonic wave emitted from the transmission unit 91b is detected by the reception unit 92a after passing through both the document D and the tag 83.
That is, the output voltage of the receiving unit 92a becomes Vb1 (<Vb) due to attenuation when ultrasonic waves emitted from the transmitting unit 91b pass through both the document D and the tag 83. Therefore, if a predetermined voltage smaller than the output voltage Vb and larger than the output voltage Vb1 is determined in advance as the threshold value th2, determination of the magnitude relationship between the output voltage of the receiving unit 92a and the threshold value th2 between time points t5 and t6. Thus, the presence / absence of the sticky note 83 can be detected.

In FIG. 13, the combination of the transmission units 91 a and 91 b and the reception unit 92 a has been described, but the same control can be performed for the combination of the transmission units 91 b and 91 c and the reception unit 92 b.
Specifically, in FIG. 13A, the transmitting unit 91a is replaced with the transmitting unit 91c, and the receiving unit 92a is replaced with the receiving unit 92b, and ultrasonic waves emitted from the transmitting units 91b and 91c are received by the receiving unit 92b. By detecting by shifting the time, the tag can be detected for each of the detection widths 70c and 70d.

  As described above, by using the ultrasonic sensor as the tag detection sensor, it is possible to predict in advance that the tag attached to the document D is in contact with any of the transport rollers by continuing the transport of the document D, and transmitting Since the number of receiving units 92 can be reduced relative to the number of units 91, the number of receiving units 92 can be reduced as compared with the configuration in which the number of transmitting units 91 and receiving units 92 is the same. Cost reduction can be realized.

In the above description, the configuration example in which ultrasonic waves are simultaneously output from the transmitters 91a and 91b on the assumption that the relationship of pulse output time Ta <delay time Tb is satisfied, but the present invention is not limited thereto.
For example, in the case where the relationship of the pulse output time Ta <delay time Tb cannot be satisfied because there is almost no difference between the distances L1 and L2, if ultrasonic waves are output simultaneously from the transmission units 91a and 91b, transmission is performed. While receiving the ultrasonic wave from the unit 91a by the receiving unit 92a, the ultrasonic wave from the transmitting unit 91b may be simultaneously received by the receiving unit 92a.

In this case, a combination of the respective ultrasonic waves is detected by the receiving unit 92a, and the received amount of ultrasonic waves from the transmitting unit 91a is distinguished from the received amount of ultrasonic waves from the transmitting unit 91b. Processing (to be described later) is required, and control is likely to be complicated.
As a method for avoiding this, instead of the configuration in which the ultrasonic waves are simultaneously output from the transmitters 91a and 91b, a configuration in which the ultrasonic output times do not overlap can be employed.

FIG. 14 is a diagram illustrating an example of a timing chart in a configuration in which the output times of ultrasonic waves from the transmission units 91a and 91b do not overlap.
As shown in the figure, an ultrasonic wave is output from the transmitter 91a between time points t1 and t2 (ON), and an ultrasonic wave is output from the transmitter unit 91b between time points t3 and t4 after the time point t2 (ON). ). The output time of the ultrasonic waves is the same pulse output time Ta for both the transmitters 91a and 91b. The time Tc from the ultrasound output start time t1 by the transmitter 91a to the ultrasound output start time t3 by the transmitter 91b is the time at which the output timing is shifted.

The ultrasonic wave output from the transmitter 91a between the times t1 and t2 is received by the receiver 92a between the times t6 and t7. The receiver 92a outputs a voltage Va corresponding to the amount of ultrasonic waves received from the transmitter 91a.
On the other hand, the ultrasonic wave output from the transmission unit 91b between the time points t3 and t4 is received by the reception unit 92a between the time points t8 and t9. The receiving unit 92a outputs a voltage Vb (<Va) corresponding to the amount of ultrasonic waves received from the transmitting unit 91b.

  Thus, after the output of the ultrasonic wave by the transmitting unit 91a closer to the receiving unit 92a is completed, the output of the ultrasonic wave by the transmitting unit 91b far from the receiving unit 92a is started, thereby transmitting the transmitting units 91a and 91b. The output time of the ultrasonic due to will not overlap. If this structure is taken, the ultrasonic wave from the transmission part 91a and the ultrasonic wave from the transmission part 91b can be separately received in a different time zone in one receiving part 92a. That is, it is possible to avoid receiving ultrasonic waves from the transmitters 91a and 91b simultaneously by the receiver 92a.

  The time Tc can be determined as follows. That is, the shorter the time Tc is, the closer the configuration is such that the ultrasonic waves from the transmitters 91a and 91b are simultaneously received by the receiver 92a. On the other hand, if the time Tc is lengthened, even if it is possible to avoid receiving the ultrasonic waves from the transmitters 91a and 91b at the receiver 92a at the same time, the single detection cycle (time points t1 to t9) of the sticky note is reduced. It becomes longer and the number of detections per unit time is reduced.

When the number of detections per unit time decreases, detection of a tag attached to the document D being conveyed is delayed, and the timing for interrupting conveyance of the document D is also delayed. As the timing of interrupting the conveyance of the document D is delayed, the sticky note already comes into contact with the transport roller before the interruption, and the sticky note is likely to break.
From this, the length of the time Tc is the minimum time necessary to avoid the ultrasonic waves from the transmitters 91a and 91b being simultaneously received by the receiver 92a or the detection variation is added to this time. It is desirable to determine the time in advance from experiments.

  In FIG. 14, the ultrasonic wave is output from the transmitter 91 a closer to the receiver 92 a, and the output of the ultrasonic wave is started from the transmitter 91 b far from the receiver 92 a after the output ends. You may output an ultrasonic wave in order of the transmission parts 91b and 91a. After receiving the ultrasonic wave from the transmitting unit 91b at the receiving unit 92a, the ultrasonic wave from the transmitting unit 91b is started so that the ultrasonic wave from the transmitting unit 91a is received at the receiving unit 92a. The sound wave output timing and output time are adjusted.

That is, the period in which the ultrasonic wave emitted from the transmitter 91a is received by the receiver 92a and the period in which the ultrasonic wave emitted from the transmitter 91b is received by the receiver 62a do not overlap. The ultrasonic wave output timing and output time of each of the transmitters 91a and 91b may be determined in advance.
From this, in FIG. 13, the output start of the ultrasonic wave from the transmission part 91b can be delayed for a while from the time point t1 to any time point between the time points t1 and t2.

In the above description, the configuration example for avoiding the ultrasonic waves from the transmitting units 91a and 91b being simultaneously received by the receiving unit 92a has been described, but instead, for example, when receiving simultaneously, It is also possible to adopt a configuration that incorporates control for distinguishing the amount (intensity) of wave ultrasound.
FIG. 15 is a diagram illustrating an example of a timing chart in a configuration in which ultrasonic waves from the transmission units 91a and 91b are simultaneously received by the reception unit 92a.

As shown in the figure, the ultrasonic waves simultaneously emitted from the transmission units 91a and 91b between the time points t1 and t2 are transmitted from the transmission unit 91a closer to the reception unit 92a to the reception unit 92a first. Arrives (time t3), and at a subsequent time t4, the ultrasonic wave emitted from the transmission unit 91b far from the reception unit 92a reaches the reception unit 92a.
The reception amount of the reception unit 92a indicates the amount of received ultrasonic waves in the reception unit 92a.

  Specifically, the reception amount between time points t3 and t4 (time Td) corresponds to the reception amount of only the ultrasonic waves emitted from the transmission unit 91a. The amount of reception between time points t4 and t5 (time Te) corresponds to the amount of reception of the synthesized ultrasonic waves emitted from both transmitters 91a and 91b. The reception amount between time points t5 and t6 (time Tf) corresponds to the reception amount of only the ultrasonic waves emitted from the transmission unit 91b. That is, if the times Td and Tf are other than the time Te at which the synthesized wave of the ultrasonic waves emitted from both the transmitters 91a and 91b is received, the ultrasonic waves emitted from the transmitters 91a and 91b are separately transmitted. Can be detected.

  In order to detect the ultrasonic waves separately at the times Td and Tf without detecting the ultrasonic waves at the time Te, the operation of the receiving unit 92a is stopped (not driven) at the time Te, and at the times Td and Tf. A method of operating the receiving unit 92a can be taken. Switching between operation and stop of the receiving unit 92a can be performed by switching between supply and stop of driving power to the receiving unit 92a from a power supply unit (not shown) that supplies driving power to the receiving unit 92a.

  The ON time signal in the figure shows a signal for switching the operation (H level) and stop (L level) of the receiving unit 92a, and is output from the document conveyance control unit 54 to the power supply unit. The power supply unit supplies driving power to the receiving unit 92a when the ON time signal is at the H level, and stops supplying driving power to the receiving unit 92a when the ON time signal is at the L level. The receiving unit 92a operates normally when the driving power is supplied, and stops operating when the driving power is stopped.

  Switching between the H level and the L level of the ON time signal is performed in synchronization with the output timing of the ultrasonic waves from the transmitters 91a and 91b. Specifically, the time Td when the ultrasonic wave emitted from the transmitter 91a is received by the receiver 92a and the time Tf when the ultrasonic wave emitted from the transmitter 91b is received by the receiver 92a are synchronized. Then, the ON time signal becomes H level. On the other hand, the ON time signal becomes L level in synchronization with the time Te at which the ultrasonic waves emitted from both the transmitters 91a and 91b are received by the receiver 92a. The switching timing of the H level and L level of the ON time signal with respect to times Td, Te, and Tf is determined in advance.

As a result, the receiving unit 92a outputs a voltage corresponding to each received ultrasonic wave only at times Td and Tf as shown in the output voltage waveform of FIG.
Therefore, by monitoring the voltages output from the receiving unit 92a at times Td and Tf, the ultrasonic waves emitted from the transmitting units 91a and 91b can be distinguished and detected by the single receiving unit 92a. By determining the magnitude relationship between the output voltage of the receiving unit 92a and a predetermined threshold value (corresponding to th1 or th2) at each time Td, Tf, it is possible to detect the presence / absence of a tag with different detection widths.

The period from time t1 to t6 corresponds to one detection cycle, and tag detection is repeatedly executed for each detection cycle in the detection cycle unit during document conveyance.
Since the drive power supply to the reception unit 92a is alternately switched between supply and stop within the detection period for each detection cycle, the drive power is constantly supplied to the reception unit 92a. Thus, low power consumption can be realized.

In the above-described FIG. 15, the configuration example in which the reception unit 92 is intermittently driven has been described, but the configuration is not limited thereto.
For example, the configuration is such that ultrasonic waves are simultaneously output from the transmitters 91a and 91b and the receiver 92a is always driven, and the distance La from the transmitter 91a to the receiver 92a and the distance Lb from the transmitter 91b to the receiver 92a. In the configuration in which the ultrasonic wave from the transmission unit 91b is received by the reception unit 92a with almost no delay with respect to the ultrasonic wave from the transmission unit 91a, as shown in FIG. It is also possible to detect the presence / absence of a tag using different thresholds th1 to th3 for D.

Here, the state A shown in FIG. 16 refers to the output voltage Va of the receiving unit 92a when no sticky note is simultaneously detected in both the detection width 70a (FIG. 12) by the transmitting unit 91a and the detection width 70b by the transmitting unit 91b. Show.
The state B indicates the output voltage Vb of the receiving unit 92a when the tag is detected with the detection width 70a by the transmitting unit 91a, but at the same time the tag is not detected with the detection width 70b by the transmitting unit 91b. .

  Similarly, the state C is the output voltage Vc of the receiving unit 92a when the tag is not detected with the detection width 70a by the transmitting unit 91a and the tag is detected with the detection width 70b by the transmitting unit 91b at the same time. Show. The state D indicates the output voltage Vd of the receiving unit 92a when a sticky note is simultaneously detected in both the detection width 70a by the transmission unit 91a and the detection width 70b by the transmission unit 91b.

  While the document is being conveyed, it should be in any of the states A to D depending on the presence or absence of a tag in the detection widths 70a and 70b. Therefore, a threshold th1 is set between the voltages Va and Vb (<Va), a threshold th2 is set between the voltages Vb and Vc (<Vb), and a threshold th3 is set between the voltages Vc and Vd (<Vc). Set it. Then, the output voltage of the receiving unit 92a is monitored every certain time (for example, several milliseconds) during document conveyance. For example, if the output voltage V of the receiving unit 92a becomes a relationship of th2 <V <th1 at a certain point in time, It can be detected that a sticky note exists in the state B, that is, the detection width 70a. As the voltages Va to Vd and th1 to th3, values suitable for the apparatus configuration are determined in advance through experiments or the like.

  In the above description, the example in which the magnitude relationship of the voltage Vd <Vc <Vb <Va has been described. However, depending on the output voltage characteristics of the receiving unit 92a, the relationship of Va <Vb <Vc <Vd may occur. If only the presence / absence of a tag is detected, if the output voltage V of the receiving unit 92a is equal to or less than the threshold th1, the tag exists in any detection width, and if it is greater than the threshold th1, any detection width may be detected. It can be detected that no sticky note exists.

In the example of FIG. 12, the configuration example in which the two reception units 92a and 92b are associated with the three transmission units 91a to 91c arranged at intervals along the width direction W has been described, but the configuration is not limited thereto. For example, when there are n (plural) roller bodies arranged in regions that do not overlap with each other along the width direction W, the following configuration may be employed.
That is, in order to detect contact of a sticky note with n roller bodies arranged at intervals along the width direction W, an arrangement region (roller width) in the width direction W for each of the n roller bodies. A detection width that is the same width or wider than Wr (FIG. 4) in the width direction W is required. It is assumed that each detection width does not overlap in the width direction W.

  Two transmitters 91 and one receiver 92 can be provided for two adjacent detection widths spaced apart in the width direction W. Specifically, the roller body adjacent to the width direction W is the first and second roller bodies, the roller body adjacent to the second roller body is the third roller body, the first, second, and third rollers. Let the roller installation area | region of the width direction W of a main body be the 1st, 2nd, 3rd detection width (equivalent to 70a, 70b, 70c of FIG. 12).

  In this case, the first transmitter 91 (corresponding to 91a in FIG. 12) is arranged opposite to the first detection width (corresponding to 70a in FIG. 12), and the second detection width (corresponding to 70b in FIG. 12). ) And a third detection width (corresponding to 70c in FIG. 12) that is adjacent to this with a gap in the width direction W, and a second transmitter 91 (corresponding to 91b in FIG. 12) is disposed. In the ultrasonic wave from the first transmitter 91, only the ultrasonic wave that has passed the first detection width can be received, and the ultrasonic wave from the second transmitter 91 passes through the second detection width. One receiving unit 92 (corresponding to 92a in FIG. 12) that can receive only the ultrasonic waves that have been received can be arranged. This is the same even if the number n of roller bodies is 5 or more.

  In other words, among the five or more roller bodies, one roller body is obtained by associating a pair of two transmitters 91 and one receiver 92 with two adjacent roller bodies (that is, two detection widths). That is, it is possible to reduce the number of at least one of the transmitting unit 91 and the receiving unit 92 as compared with a configuration in which a set of one transmitting unit 91 and one receiving unit 92 is associated with one detection width. For example, when the number N (= n) of detection widths is 4 or more, the number of transmitting units 91 can be (N−1) and the number of receiving units 92 can be (N−2).

In addition, it is not restricted to said structure, It is good also as a structure which matches the group of the one transmission part 91 and the one receiving part 92 with respect to one roller main body (namely, one detection width).
In the above description, the transmitting unit 91 is disposed on the upper side with the document conveying path 401 interposed therebetween, and the receiving unit 92 is disposed on the lower side. However, the present invention is not limited thereto, and the transmitting unit is disposed on the lower side with the document conveying path 401 interposed therebetween. 91 may be arranged, and the receiving unit 92 may be arranged on the upper side.

  The present invention is not limited to a sheet conveying apparatus that conveys a sheet such as a document, and may be a sheet conveying method, for example. Furthermore, the method may be a program executed by a computer. The program according to the present invention includes, for example, a magnetic disk such as a magnetic tape and a flexible disk, an optical recording medium such as a DVD-ROM, DVD-RAM, CD-ROM, CD-R, MO, and PD, and a flash memory recording medium. It can be recorded on various computer-readable recording media, and may be produced, transferred, etc. in the form of the recording medium, wired and wireless various networks including the Internet in the form of programs, In some cases, the data is transmitted and supplied via broadcasting, telecommunication lines, satellite communications, or the like.

<Modification>
As described above, the present invention has been described based on the embodiment. However, the present invention is not limited to the above-described embodiment, and the following modifications may be considered.
(1) In the above embodiment, the sticky note 82 is detected for the document D after the feeding roller 41 starts feeding, but the present invention is not limited to this. Any configuration that can predict in advance whether or not a sticky note attached to the document D comes into contact with any one of the transport rollers (that is, the roller body) by transporting the document for each document D is acceptable. .

  For example, the sticky note detection sensor 8 including a distance measuring sensor is disposed at a position Pb (FIG. 2) upstream of the feeding roller 41 and in the vicinity of the feeding roller 41 and in contact with each of the feeding rollers including the feeding roller 41. It can also be configured to predict the presence or absence of a sticky note. In this way, even a sticky note in contact with the feeding roller 41 can be detected before contacting the feeding roller 41.

In addition, when there is a sensor that can detect a sticky note two-dimensionally for the entire front surface (upper surface) of the document D set on the document feed tray 40a and stopped, the document It is also possible to predict the presence or absence of a sticky note in contact with the transport roller before the start of transport.
(2) In the above-described embodiment, the separation roller pair 42, the intermediate roller pair 43, and the like have been described with respect to a configuration example in which a plurality of roller bodies are provided with a single rotation axis in the width direction W. I can't. For example, a configuration in which one roller main body 421 is provided on the rotation shaft 433 and a plurality of roller main bodies 431 are provided on the rotation shaft 443 can be employed. The roller width, the number, the arrangement position, etc. of each roller body suitable for the apparatus configuration are determined.

(3) In the above embodiment, the configuration example in which the detection widths 7a to 7e on the document conveyance path 401 by the sticky note detection sensors 8a to 8e are equal to the widths 7a to 7e of the roller installation areas 9a to 9e has been described. Not limited to. It is only necessary to detect that at least a part of the sticky note attached to the document D has entered one of the roller installation areas 9a to 9e.
For example, a sticky note detection sensor 8a in which the detection width is set to a width longer than a width 7a of the roller installation area by a predetermined value (about several mm) can be used. By assuming that the detection width is a little wider than the width 7a of the roller installation area, even if the detection width of the sticky note detection sensor 8a includes manufacturing variations, it is assumed that the document D is brought into contact with the conveyance roller by continuing the conveyance. It becomes possible to detect a sticky note to be detected more reliably in advance. The same applies to the other tag detection sensors 8b to 8e. The slightly wider area including this variation can be regarded as a roller installation area, and a length in the width direction equal to this can be determined as the detection width of the tag detection sensors 8 and 90. If the detection width is set to be larger than the width of the roller installation area, the sticky note may be detected in advance as a touching sticky note even if the sticky note does not contact any of the transport rollers during transport. For this reason, even if the detection width is widened, it is desirable to set the upper limit to the range in which the above variation can be absorbed.

(4) In the above-described embodiment, a configuration example has been described in which a plurality of tag detection sensors 8 are arranged at intervals along the width direction W corresponding to the arrangement positions of the plurality of transport rollers in the width direction W. However, it is not limited to this.
For example, the sticky note detection sensor 8a shown in FIG. 3 is arranged upstream of the roller body 451 positioned at the most upstream among the plurality of roller bodies 451, 461, 471, 481 arranged along the document transport direction X. Further, it may be arranged at a position close to the roller body 451. The same applies to the other tag detection sensors 8b to 8e.

  (5) In the above embodiment, an example in which the sheet conveying apparatus of the present invention is applied to an automatic document conveying unit has been described. However, a sheet to be conveyed is not limited to a document. For example, the present invention can be applied to a sheet conveying apparatus that conveys a sheet used for image formation in an image forming apparatus such as a printer. Specifically, the present invention can be applied to a configuration in which the sheets S accommodated in the sheet feeding cassette 31 shown in FIG. 1 are fed out one by one and conveyed by each conveying roller such as the secondary transfer roller 21.

  Further, the configurations of the above embodiment and the above modification may be combined as much as possible.

  The present invention can be widely applied to a sheet conveying apparatus that conveys a sheet such as a document or paper.

4 Operation section 5 Overall control section 6 Transport motors 7a, 7b, 7c, 7d, 7e Detection width 9a, 9b, 9c, 9d, 9e First area 8 Sticky note detection sensor 40 Automatic document transport section 41 Feeding roller 42 Separating roller pair 43 Intermediate roller pair 44 Registration roller pair 45 Pre-reading roller pair 46 Post-reading roller pair 47 Pre-discharge roller pair 48 Pre-discharge roller pair 54 Ejection roller 54 Document transport control unit 81, 82, 83 Sticky 90 Ultrasonic sensor 91a, 91b, 91c Transmitter unit 92a, 92b Receiving section 93a, 93b, 93c, 93d, 93e Second area 401 Document transport path 421, 431, 441, 451, 461, 471, 481 Roller body D Document P Detection position W Width direction of transport path X Document transport direction

Claims (13)

A sheet conveying apparatus that conveys a sheet by a plurality of conveying rollers along a conveying path,
Predicting means for predicting whether or not a sheet piece such as a tag or tag attached to the surface of the sheet is brought into contact with any of the plurality of transport rollers by transport of the sheet to be transported
When it is predicted that the contact state will not occur, the sheet is transported by the rotation of the transport rollers. When the contact state is predicted, the transport roller is stopped. Control means for controlling the rotation of the respective conveying rollers so that the sheet is not conveyed;
A sheet conveying apparatus comprising: The control means includes
The sheet conveying apparatus according to claim 1, wherein the sheet conveyance is interrupted when the contact state is predicted after the sheet conveyance start. A notification means for notifying a user of predetermined information;
The control means includes
3. The sheet conveying apparatus according to claim 2, wherein when the conveyance of the sheet is interrupted, the notification unit is notified as the predetermined information that the conveyance of the sheet is interrupted due to adhesion of the sheet piece. The prediction means includes
A position detecting means for detecting a position of the sheet piece adhering to the surface of the sheet on the sheet;
The control means includes
The sheet conveying apparatus according to claim 3, wherein the notifying unit is notified of the detection position of the sheet piece as the predetermined information. The control means includes
After the conveyance of the sheet is interrupted, the respective conveyance rollers are rotated in a direction opposite to the rotation direction during the conveyance, thereby conveying the sheet in a direction opposite to the sheet conveyance direction toward a position before the conveyance is started. The sheet conveying apparatus according to claim 2, wherein the sheet conveying apparatus is a sheet conveying apparatus. Each of the plurality of transport rollers is
A roller in which a plurality of roller bodies are provided in the width direction at intervals on a rotation axis along the width direction orthogonal to the sheet conveyance direction, and a conveyance roller in which one roller body is provided on the rotation axis. One of them, and arranged at intervals along the sheet conveying direction,
On the transport path,
A first region in which any one of the roller bodies exists at any position between the upstream side and the downstream side in the sheet conveyance direction along the sheet conveyance direction, and none of the roller bodies exists at any position. A second region exists,
The prediction means includes
During the conveyance of the sheet, the sheet piece having at least a part in the first area is conveyed in the sheet conveyance direction with respect to the roller main body located most upstream in the sheet conveyance direction among the roller main bodies existing in the first area. A sheet piece detecting means for detecting on the upstream side,
The contact state is not predicted until the sheet piece is detected, and the contact state is predicted when the sheet piece is detected. The sheet conveying apparatus according to item 1. A tray on which sheets are placed;
A feeding roller that feeds sheets one by one from the bundle of a plurality of sheets placed on the tray to the downstream side in the sheet conveying direction;
A sheet feeding roller that is disposed downstream of the feeding roller in the sheet conveying direction and closest to the feeding roller, and further conveys the sheet fed by the feeding roller further downstream in the sheet conveying direction on the conveying path;
With
The feeding roller is not included in the plurality of transport rollers,
The paper feed roller is one of the plurality of transport rollers, and is positioned upstream of the other transport rollers in the sheet transport direction,
The sheet piece detecting means includes
The detection is performed when the sheet fed by the feeding roller passes through a predetermined detection position downstream of the feeding roller in the sheet conveying direction and upstream of the paper feeding roller in the sheet conveying direction. The sheet conveying apparatus according to claim 6. The sheet piece detecting means includes
A transmitter that emits ultrasonic waves and a receiver that receives ultrasonic waves emitted from the transmitter;
The sheet conveying apparatus according to claim 6, wherein the transmitting unit is disposed on one side of the conveying path, and the receiving unit is disposed on the other side. The sheet piece detecting means includes a plurality of the transmitting units,
The plurality of transmitters include first and second transmitters,
On the transport path, there are two first regions on both sides in the width direction across the second region,
The first transmitter, the second transmitter, and the receiver are emitted from the first transmitter, the ultrasonic wave that has passed through the first region, and the second transmitter. The sheet conveying apparatus according to claim 8, wherein each of the ultrasonic waves emitted from the first region and passing through the other first region is disposed at a position where the receiving unit can receive the ultrasonic waves.   A period during which the ultrasonic wave emitted from the first transmitter is received by the receiver and a period during which the ultrasonic wave emitted from the second transmitter is received by the receiver. The sheet conveying apparatus according to claim 9, wherein an output timing and an output time of ultrasonic waves by each of the first transmitter and the second transmitter are determined in advance so as not to overlap. . Each of the first and second transmitters outputs ultrasonic waves for the same time Ta at the same time,
The super-radiation generated from the first transmitter is caused by the difference between the distance La from the first transmitter to the receiver and the distance Lb (> La) from the second transmitter to the receiver. When the delay time of the arrival timing of the ultrasonic wave emitted from the second transmitting unit to the sound wave to the receiving unit is Tb,
The sheet conveying apparatus according to claim 10, wherein a relationship of Ta <Tb is satisfied.   The sheet conveying apparatus according to claim 10, wherein output of ultrasonic waves from the second transmitter is started after completion of output of ultrasonic waves from the first transmitter. In the case of a configuration in which ultrasonic waves emitted from each of the first transmitter and the second transmitter are simultaneously received by the receiver,
Va is the output voltage of the receiving unit in the state A where the sheet pieces are not detected simultaneously in both the one first region and the other first region,
The output voltage of the receiving unit when the sheet piece is detected in the one first area and the sheet piece is not detected in the other first area at the same time is Vb,
The output voltage of the receiving unit when the sheet piece is not detected in the one first region and the sheet piece is detected in the other first region at the same time is Vc,
When the output voltage of the receiving unit in the state D in which the sheet pieces are detected simultaneously in both the one first region and the other first region is Vd,
Voltage Vd <Vc <Vb <Va or voltage Va <Vb <Vc <Vd,
The sheet piece detecting means includes
A threshold th1 is set between the voltages Va and Vb, a threshold th2 is set between the voltages Vb and Vc, a threshold th3 is set between the voltages Vc and Vd, and the output voltage of the receiving unit and the threshold th1 The sheet conveying apparatus according to claim 9, wherein presence / absence of the sheet piece in each of the first region and the other first region is detected from a magnitude relationship with .about.th3.

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