JP2009246747A - Automatic document feeder and image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic document feeder and an image reader that stably secure productivity even if various conditions of a mechanism, a basic feeding speed, etc., change. <P>SOLUTION: The automatic document feeder includes a controller 100 which sets an operation mode to either a stop mode wherein the feeding operation is stopped to stop the document at a stop position (the position of a read entrance roller 16) and then restarted to feed the document to a read position 20 or a non-stop mode wherein the document is fed to the read position 20 without being stopped at the stop position when a read entrance sensor 15 detects that the document has reached the stop position in feeding the document to the read position 20. The document feeder also sets the operation mode to the stop mode and controls the feeding of the document based upon the set operation mode when a predetermined condition is met before a time limit in determining the stop mode or non-stop mode as the operation mode. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an automatic document conveyance device and an image reading device, and more particularly to a sheet-through type automatic document conveyance device that conveys a document to a fixed reading position and an image reading device including the automatic document conveyance device.

  Conventionally, in this type of automatic document feeder, the conveyance operation is temporarily stopped during the conveyance of the document to the reading position, and the conveyance operation is resumed when a reading start signal is received from the image forming apparatus main body as the image reading device. There is known a mode including a mode and a non-stop mode in which a document is conveyed to a reading position without being stopped (see, for example, Patent Document 1).

  Here, the stop mode and the non-stop mode will be described.

  FIG. 11 is a timing chart showing the conveying operation in the stop mode of the conventional automatic document feeder. FIG. 12 is a timing chart showing the conveying operation in the non-stop mode of the conventional automatic document feeder. FIG. 13 is a diagram showing an operation result of the conventional automatic document feeder.

  As shown in FIG. 11, in the conventional automatic document feeder, when the operation mode is the stop mode, the forward rotation (downward on the vertical axis) and reverse rotation (upward on the vertical axis) of the paper feed motor, and the reading motor The original is conveyed by normal rotation (upward on the vertical axis). In the stop mode, when continuous reading control for continuously reading a plurality of originals is performed, the originals come into contact with a reading entrance roller near the upstream of the reading position and stop and wait for this original (Tmc). It is necessary to stop the document preceding the preceding document immediately after the reading of the preceding document is completed (timing indicated by Tme), and stop at the timing of completion of stopping the preceding document (Tme). Therefore, it is necessary to control the resumption and stop of the subsequent document that has been waiting. This is because the reading entrance roller on which the succeeding document abuts and waits is the same as the driving system of the roller group that carries the preceding document, so that the abutting operation of the document to the reading entrance roller is ensured. In order to do this, it is necessary to perform control so that the rotation of the reading entrance roller is stopped in advance with sufficient margin, and then the succeeding document is abutted against the reading entrance roller and stopped.

  On the other hand, as shown in FIG. 12, in the conventional automatic document feeder, when the operation mode is the non-stop mode, the forward rotation (downward on the vertical axis) and the reverse rotation (upward on the vertical axis) of the paper feeding motor. Then, the original is conveyed by normal rotation of the reading motor (upward on the vertical axis). In the non-stop mode, when continuous reading control for continuously reading a plurality of documents is performed, the interval between the preceding document read at the reading position and the document following this document (document interval L) is controlled. Therefore, it is necessary to appropriately control the conveyance of the subsequent document.

  That is, when the image reading device reads a document conveyed by the automatic document conveying device, even if the document conveying interval is narrowed to the minimum interval that can be operated on the automatic document conveying device side, reading and other processes are performed on the image reading device side. Since the operation may be hindered without being in time, the manuscript interval in the automatic manuscript conveying device is maximized so that the productivity (the number of manuscripts that can be processed per unit time) is maximized within the range that does not hinder the operation of the image reading apparatus. Must be controlled.

  In the conventional automatic document feeder, control is performed on the premise of the stop mode when neither the stop mode nor the non-stop mode is specified (indeterminate state), but the operation is based on the stop mode. The latest timing at which the non-stop mode can be changed is the timing at which the paper feed motor starts decelerating (Tmb in FIG. 11) or the timing at which the reading motor that transports the preceding document starts decelerating (Tmb in FIG. 11). This is the earlier of Tmd) in FIG.

  FIG. 13 summarizes these. Item A in the top row shows the transition of the operation prohibited state in the non-stop mode, and item B in the second row shows the transition of the operation prohibited state in the stop mode. Item C in the third row shows a transition of a state in which the transition to the non-stop mode is possible. Item D in the fourth row and item E in the fifth row indicate operation results related to the operation mode and productivity set according to the timing at which the reading start signal is received from the image reading apparatus.

  The conditions shown here are only examples, and vary depending on various modes related to document conveyance (for example, single-sided reading mode or double-sided reading mode), productivity achieved as a system, mechanical mechanism, basic speed of document conveyance, etc. However, each relationship is not constant.

Against such a technical background, the automatic document feeder described in Patent Document 1 receives a reading start signal from the image reading device before a specific determination timing such as the timing at which the document reaches the reading position. In this case, the document interval is shortened by changing the operation from the stop mode to the non-stop mode.
JP 2006-333528 A

  However, in the conventional automatic document feeder as described above, the operation mode is determined based only on the timing at which the reading start signal is received, and the transmission / reception timing of the reading start signal varies. As shown in item D of FIG. 13, there is a control delay due to some cause in at least one of the image reading apparatus that transmits and receives the reading start signal and the automatic document feeder, as shown in item D of FIG. When the reading start signal has not been transmitted / received by the determination timing indicated by Ta in FIG. 13, as shown as D2 in item D in FIG. Therefore, there is a problem that productivity is remarkably lowered.

  Further, as shown in the item E in the fifth row in FIG. 13, the determination timing for the transition to the non-stop mode is set to Tb later than Ta, so that there is a time margin for transmission / reception of the read start signal and the like. In this case, the fastest operation possible in the operation in the stop mode (which can shorten the document interval) cannot be performed, and a delay is caused by Tb-Ta, so that the productivity in the operation in the stop mode is unnecessarily reduced. There was a problem to do. That is, when the operation is to be performed in the stop mode using Tb as the determination timing, the timing of restarting the document conveyance is also delayed by the amount that the document stop timing is delayed as compared with the case where Ta is set as the determination timing. Therefore, the productivity drop is particularly serious when a plurality of documents are continuously conveyed while repeating the stop mode operation, and the shading operation and other operations in which the reading unit performs adjustment on the image reading apparatus side. Therefore, even when a stop mode is mixed at regular intervals during continuous conveyance and reading of a plurality of documents, the total productivity is lowered.

  On the other hand, in order to improve productivity, the reading start signal is transmitted and received between the image reading apparatus and the automatic document feeder at a timing sufficiently earlier than the determination timing indicated by Ta. In such a case, it is not the safest timing in terms of control, and the parting control is performed so that the image reading device sends the reading start signal to the automatic document feeder in advance at the timing when the time until the end of specific control such as shading is anticipated. Therefore, there is a problem that stable operation cannot be performed and reliability of the entire system is lowered.

  The present invention has been made to solve the above-described conventional problems, and can automatically ensure productivity even when various conditions such as a mechanical mechanism and a basic conveyance speed change. An object of the present invention is to provide a document conveying device and an image reading device.

  An automatic document conveying apparatus according to the present invention can be mounted on an image reading apparatus that can read a document to be conveyed at a fixed reading position, and the document is conveyed one by one to the reading position. Detecting means for detecting that the document has reached a stop position near the upstream of the reading position, and detecting that the document has reached the stop position by the detecting means when conveying the document to the reading position. In this case, the transport operation is stopped and the document is stopped at the stop position, and then the transport operation is restarted and the document is transported to the reading position, and the reading position is stopped without stopping at the stop position. An operation mode setting means for setting an operation mode to any one of the non-stop modes for conveyance, and the operation mode is set to either the stop mode or the non-stop mode. When the predetermined condition is satisfied before the determination deadline for determining the operation mode, the operation mode setting unit sets the operation mode to the stop mode, and the operation mode setting unit sets the operation mode to the operation mode set by the operation mode setting unit. And a conveyance control means for controlling the conveyance of the document based on the above.

  With this configuration, whether or not the predetermined condition for setting the stop mode is satisfied is determined before the determination deadline, and if the predetermined condition is satisfied, the operation mode is set to the stop mode. In either case of the mode or the non-stop mode, it is possible to perform optimal control in terms of productivity, and the operation mode can be set with a margin with respect to the variation that occurs in the information that is the basis for the determination. Therefore, even when various conditions such as the mechanical mechanism and the basic conveyance speed change, productivity can be stably secured.

The automatic document feeder according to the present invention includes a conveyance mode setting unit that sets a conveyance mode to a continuous conveyance mode in which a plurality of documents are continuously conveyed to the reading position by the conveyance control unit.
When the transport mode is set to the continuous transport mode, the transport control means sets the document so that the interval between the preceding document and the succeeding document is the smallest possible in the mechanism. It is transported.

  With this configuration, since the interval between documents conveyed continuously is controlled to be as narrow as possible in structure, it is possible to achieve high productivity stably.

  The automatic document feeder according to the present invention further comprises stop mode designation signal receiving means for receiving a stop mode designation signal transmitted by the image reading device when the image reading device is readable. When the operation mode is indeterminate and the stop mode designation signal is received by the stop mode designation signal reception means before the determination deadline, the operation mode is set by the operation mode setting means. The stop mode is set, and the transport control unit restarts the transport operation of the document as soon as the operation in the stop mode becomes possible.

  With this configuration, the operation is performed in cooperation with the image reading apparatus, and the conveyance operation when intentionally performing the operation in the stop mode is optimized as the entire system, and can be performed quickly and stably without waste.

  The automatic document feeder according to the present invention includes a reading start signal receiving means for receiving a reading start signal transmitted by the image reading apparatus when the image reading apparatus is readable, and the operation mode is not yet determined. A non-stop mode setting means for setting the operation mode to the non-stop mode by the operation mode setting means when the read start signal is received by the read start signal receiving means before the determination deadline. And the conveyance control means resumes the document conveyance operation as soon as the operation in the non-stop mode is enabled.

  With this configuration, the operation is performed in cooperation with the image reading apparatus, and the conveyance operation when intentionally performing the operation in the non-stop mode is optimized as the entire system, and can be performed quickly and stably without waste. .

  Further, in the automatic document feeder according to the present invention, the conveyance control means is in a state where the operation mode is unconfirmed, the operation in the stop mode is possible, and in the non-stop mode. The document transport operation is resumed as soon as the operation becomes possible.

  With this configuration, even if the operation mode is indeterminate, the stop mode designation signal or the read start signal transmission delay or reception delay is caused by performing the transport operation as soon as the stop mode and non-stop mode operations are possible. When it happens, it is possible to avoid unnecessarily delaying the conveyance control.

  In the automatic document feeder according to the present invention, the determination deadline is the same timing as the latest timing at which the operation mode can be set to the non-stop mode, or the latest timing in terms of mechanism and control. It is characterized by earlier timing.

  With this configuration, the transition to non-stop mode operation is delayed as much as possible in terms of mechanism and control, so that even if there are some variations in control, there is no significant delay in productivity. can do.

  Further, in the automatic document feeder according to the present invention, when the operation mode setting means sets the operation mode to the non-stop mode or the document independently for each document when the conveyance mode is set to the continuous conveyance mode. The stop mode is set.

  With this configuration, the setting of the non-stop mode and the stop mode can be set independently for each document, so that possible operations for continuous document scanning can be diversified.

  The automatic document feeder according to the present invention further includes an abutting member that is provided at the stop position and against which the document to be stopped abuts, and the conveyance control unit is configured so that the operation mode is set to the stop mode. The original is stopped in a state where the original is abutted against the abutting member.

  With this configuration, the document being conveyed is abutted against the abutting member during the operation in the stop mode, thereby correcting the skew of the document that occurs during document conveyance and improving the conveyance quality.

  In the automatic document feeder according to the present invention, the abutting member also serves as a document conveying member that conveys a document.

  With this configuration, the abutting member also serves as the document conveying member, so that the number of parts can be reduced and the configuration can be simplified.

  In addition, the automatic document feeder according to the present invention includes a timing unit that counts the time during which the non-stop mode continues, and the stop mode setting unit counts the time before the determination time limit. When the time is equal to or longer than a predetermined time, the operation mode setting means sets the operation mode to the stop mode, and the conveyance control means conveys the document as soon as the operation in the stop mode becomes possible. The operation is resumed.

  With this configuration, it is possible to determine whether or not to shift to the stop mode by measuring the duration of continuous execution of the non-stop mode, and the image reading apparatus It is possible to perform an optimum operation without extra communication.

  In the automatic document feeder according to the present invention, when the conveyance control unit sets the operation mode to the non-stop mode and the conveyance mode is set to the continuous conveyance mode, the document interval is Is characterized in that the document is conveyed so as to be a predetermined document interval.

  With this configuration, by setting the document interval at the time of setting the continuous conveyance mode to the specified document interval, a stable conveyance operation can be performed.

  The automatic document feeder according to the present invention further comprises designated document interval receiving means for receiving the designated document interval from the image reading device, wherein the conveyance control means receives the document interval by the designated document interval receiving means. The document is conveyed so that the specified document interval is set.

  With this configuration, since the document interval is controlled to the designated document interval designated by the image reading device, it is possible to perform a stable conveyance operation corresponding to various operations and situations of the image reading device.

  According to another aspect of the present invention, there is provided an image reading apparatus including the automatic document feeder.

  With this configuration, the image reading apparatus includes the automatic document feeder according to the present invention, so that the entire system can stably perform system operations with high productivity in response to various situations and control requirements. It becomes.

  According to the present invention, it is possible to provide an automatic document feeder and an image forming apparatus capable of stably ensuring productivity even if various conditions such as a mechanical mechanism and a basic conveyance speed change.

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

  FIG. 1 is a schematic configuration diagram of an automatic document feeder and an image reading apparatus equipped with the automatic document feeder according to an embodiment of the present invention. FIG. 2 is a configuration diagram of an automatic document feeder according to an embodiment of the present invention. FIG. 3 is a block diagram of a control system of the automatic document feeder according to the embodiment of the present invention. The image reading apparatus provided with the automatic document feeder is configured as an image forming apparatus, and the image forming apparatus can be applied to a copying machine, a facsimile apparatus, a multifunction machine having a copying function and a facsimile function, and the like. It can be done.

  First, the configuration will be described.

  As shown in FIGS. 1 and 2, the image forming apparatus 70 includes an automatic document feeder 50 that transports a document, and an image forming apparatus main body 60 that serves as an image reader that reads a document and forms an image on a transfer sheet. And. The automatic document feeder 50 is provided so as to be openable and closable with respect to the image forming apparatus main body 60 via a hinge mechanism (not shown).

  An image reading unit 81 is provided in the image forming apparatus main body 60, and image information read by the image reading unit 81 is applied to the photosensitive drum 83 by the writing unit 82.

  The image reading unit 81 includes a light source 81a that illuminates a document on the contact glass 22 or the slit glass 21, a first mirror 81b, a second mirror 81c, a third mirror 81d that reflect light reflected from the document, and a first mirror 81d. A lens 81e that forms an image of the light reflected from the three mirrors 81d on the CCD image sensor 81f and a CCD image sensor 81f that converts the light imaged by the lens 81e into an electrical signal are provided.

  The light source 81a and the first mirror 81b are attached to a first traveling body (not shown), and the second mirror 81c and the third mirror 81d are attached to the second traveling body, and the first traveling body and the second traveling body. The body moves along the contact glass 22 and the slit glass 21.

  When the first traveling body and the second traveling body read a document placed on the contact glass 22, the first traveling body and the second traveling body are moved in the left-right direction in FIG. When reading, it is stopped below the slit glass 21.

  The writing unit 82 irradiates a laser beam light-modulated according to the image information read by the image reading unit 81, and exposes the surface of the charged photosensitive drum 83 with the laser beam.

  Around the photosensitive drum 83, a developing device 86, a transfer belt 87, a cleaning device 88, a charging device and a static eliminating device (not shown) that form an image forming unit together with the photosensitive drum 83 are provided. The charging device controls the corona discharge with a positive charge in the dark by a grid to charge the surface of the photosensitive drum to a constant potential.

  The writing unit 82 irradiates a laser diode containing image information onto the photosensitive drum 83 charged at this constant potential to remove negative charges on the photosensitive drum 83 to form an electrostatic latent image.

  The developing device 86 forms a visible image by attaching a negatively charged toner to the electrically removed portion on the photosensitive drum 83. A positive bias is applied to the transfer belt 87, and the transfer belt 87 transfers a negatively charged visible image onto a transfer sheet (paper) as a recording medium for conveyance.

  The cleaning device 88 is provided with a cleaning blade, and scrapes off the toner remaining on the photosensitive drum 83. The static eliminator turns on the internal LED to remove the residual charge on the photosensitive drum 83 and prepares to form a new image on the next transfer sheet.

  The transfer paper on which an image has been formed by the above process is conveyed to the fixing device 90 and the toner image is fixed by the fixing device 90.

  The image forming apparatus main body 60 is provided with storage cassettes 91 to 95 in which transfer papers of different sizes are stored, and the transfer paper stored in the storage cassettes 91 to 95 is called by calling rollers 91a to 95a. After being fed by the paper feed rollers 91b to 95b and the paper feed rollers 91b to 95b rotating in the transport direction and separated by the reverse rollers 91c to 95c rotating in the separation direction, the relay roller pair 96, The sheet is conveyed to a registration roller pair 98 through 97, and is timed by the registration roller pair 98 to be conveyed to a conveyance path between the photosensitive drum 83 and the transfer belt 87.

  On the other hand, as shown in FIG. 2, the automatic document feeder 50 includes a document table 2 on which a document bundle 1 composed of a plurality of documents is placed with the document surface facing upward, and a document bundle placed on the document table 2. 1. Pickup roller 7 for conveying the topmost document from 1; paper feed belt 9 and reverse roller 10 for separating the document conveyed by the pickup roller 7; A pull-out roller 12, an intermediate roller 14, and a reading entrance roller 16 that conveys to the vicinity of the slit glass 21, a reading roller 19 that conveys the original conveyed to the vicinity of the slit glass 21 while making contact with the slit glass 21, and the slit glass A reading exit roller 23 that further conveys a document that has been read at a reading position 20 of 21, and a reading exit roller 23 Ri and discharge rollers 28 for discharging the conveyed original, and a discharge tray 29 ejected documents is placed.

  The document placed on the document table 2 passes through each part of the transport path before being discharged to the discharge tray 29. The conveyance path includes a document setting unit A on which the document bundle 1 is placed, a separation feeding unit B that separates and feeds one document from the placed document bundle 1, and a feeding document. A registration unit C that draws and conveys a document after alignment, a turn unit D that turns the conveyed document and conveys the document surface downward, and a surface of the document. A first reading conveyance unit E that reads from below the slit glass 21, a second reading conveyance unit F that reads the back side of the document, a paper discharge unit G that discharges the document whose front and back sides have been read out, and a discharge unit G And a stack portion H on which a document is placed. Here, the front surface of the document refers to the surface that faces upward on the document table 2 and is read by the first reading / conveying section E, and the back surface of the document faces downward on the document table 2 and corresponds to the second reading / conveying section F. This is the surface where reading is performed.

  As shown in FIG. 3, the automatic document feeder 50 includes a controller 100 that controls the entire automatic document feeder 50. The automatic document feeder 50 also includes a registration sensor 17, a document set sensor 5, a paper discharge sensor 24, an abutment sensor 11, a document width sensor 13, a reading entrance sensor 15, a sensor for inputting a signal to the controller 100. A paper proper position sensor 8 and a home position sensor 6 are provided. The automatic document feeder 50 also includes a second reading unit 25, a pickup motor 101, a paper feed motor 102, a reading motor 103, a paper discharge motor 104, a bottom plate lift, and the like as an actuator that controls driving by outputting a signal from the controller 100. A motor 105 is provided.

  The image forming apparatus main body 60 includes a main body control unit 111 that controls the image forming apparatus main body 60 and an operation unit 108 that performs various input operations and operation instructions. The controller 100 and the main body control unit 111 are connected via the I / F 107, and data such as a control signal is exchanged between them.

  FIG. 4 is a block diagram showing the configuration of the image reading unit of the automatic document feeder according to the embodiment of the present invention.

  As shown in FIG. 4, the second reading unit 25 includes a light source unit 200 that irradiates light on a document based on a lighting signal from the controller 100, a plurality of sensor chips 201 that receive reflected light from the document, A plurality of amplifying units 202 that amplify signals output from the sensor chip 201, an A / D 203 that converts the amplified signals from analog signals to digital signals, and an image processing unit 204 that performs image processing on the digitally converted signals. A frame memory 205 that stores the image-processed signal, an output control circuit 206 that controls output of the signal stored in the frame memory 205 based on a timing signal from the controller 100, and a signal from the output control circuit 206 Is provided to the main body control unit 111. The second reading unit 25 is supplied with power from the controller 100.

  Here, the detailed configuration of the automatic document feeder 50 will be described according to the order in which the documents placed on the document table 2 are discharged to the discharge tray 29.

  First, a document bundle 1 composed of a plurality of documents is placed on a document table 2 including a movable document table 3 with the surface facing upward. Next, the position in the width direction of the document bundle 1, that is, the position in the direction orthogonal to the conveyance direction is positioned by a side guide (not shown). The placement of the document on the document table 2 is detected by the set filler 4 and the document set sensor 5, and a detection signal is output to the main body control unit 111 of the image forming apparatus main body 60 via the I / F 107.

  An outline of the length of the document in the conveyance direction is detected by document length detection sensors 30 and 31 provided on the surface of the document table 2. As the document length detection sensors 30 and 31, a reflection type sensor that detects without contact with the document by optical means or a contact type actuator that can detect even when there is only one document can be used. . The document length detection sensors 30 and 31 are arranged so that it can be determined whether the document is placed vertically or horizontally.

  The movable document table 3 is configured to move up and down in the directions of arrows a and b in FIG. When it is detected by the set filler 4 and the document set sensor 5 that the document is placed on the document table 2, the controller 100 rotates the bottom plate raising motor 105 in the normal direction so that the uppermost document in the document bundle 1. The movable document table 3 is raised so as to come into contact with the pickup roller 7. Hereinafter, the position where the uppermost document of the document bundle 1 contacts the pickup roller 7 is referred to as an appropriate feeding position.

  The pickup roller 7 is operated by the pickup motor 101 in the directions of arrows c and d in FIG. 2 via the cam mechanism, and is pushed by the document on the raised movable document table 3 and lifted in the direction of arrow c. An upper limit of movement is detected by the position sensor 8. The proper paper feed position sensor 8 is a sensor for detecting that the movable original table 3 is raised and the uppermost original of the original bundle 1 is maintained at an appropriate height.

  When the operation unit 108 is operated to specify either the double-side mode or the single-side mode, the print key is pressed, and a document feed signal is output from the main body control unit 111 to the controller 100 via the I / F 107. The controller 100 rotates the pickup roller 7 by rotating the paper feed motor 102 forward. The pick-up roller 7 that has started rotating picks up the uppermost document on the document table 2 or several documents including the uppermost document.

  Next, when the paper feeding motor 9 is rotated forward by driving the paper feeding belt 9 and the reverse roller 10 clockwise, the paper feeding belt 9 guides the original in the paper feeding direction, and the reverse roller 10 sets the original in the paper feeding direction. Since the document is pushed out in the opposite direction, the uppermost document in the document bundle 1 and the document below it are separated, and only the uppermost document is fed.

  Specifically, the reverse roller 10 is in contact with the paper feed belt 9 at a predetermined pressure, and in the state of being in direct contact with the paper feed belt 9 or in the state of being in contact with one original, the paper feed belt 9. 9 is rotated in a counterclockwise direction different from the original driving direction by the action of a torque limiter (not shown). Further, when two or more documents enter between the paper feed belt 9 and the reverse roller 10, the reverse roller 10 does not rotate with the paper feed belt 9, but rotates in the clockwise direction, which is the original driving direction. It works to push back excess originals and prevent double feeding.

  The original separated by the action of the paper feeding belt 9 and the reverse roller 10 is sent by the paper feeding belt 9, and then the leading edge of the original is detected by the abutting sensor 11, and further conveyed and stopped. The pull-out roller 12 is in contact with the pull-out roller 12. Next, when the original fed by a predetermined distance from the position detected by the abutting sensor 11 is pressed against the pull-out roller 12 with a predetermined amount of deflection, the paper feed motor 102 is stopped and the paper feed belt 9 is stopped. The drive stops. At this time, the pickup motor 101 is rotated to retract the pickup roller 7 from the upper surface of the document, and the document is fed only by the conveying force of the paper feed belt 9, whereby the leading edge of the document is sandwiched between the pull-out rollers 12 and Matching, so-called skew correction is performed. The pull-out roller 12 has a skew correction function and is used to convey the skew-corrected document after separation to the intermediate roller 14 and is driven by the reverse rotation of the paper feed motor 102. When the paper feed motor 102 rotates in the reverse direction, the pull-out roller 12 and the intermediate roller 14 are driven, but the pickup roller 7 and the paper feed belt 9 are not driven.

  The document width sensor 13 is composed of a plurality of photoelectric conversion elements such as a contact image sensor called CIS arranged in a direction perpendicular to the document transport direction, and is not shown in the figure disposed at the opposite portion of the transport path. The light reception level of the direct light emitted from the irradiation light source is output. When the document passes the position of the document width sensor 13, the controller 100 detects a level difference between a portion shielded by the document and a portion not shielded by the document width sensor 13, and is conveyed by the pull-out roller 12. The size of the document in the width direction is determined and notified to the main body control unit 111. The length of the document in the conveyance direction is detected from the motor pulse by reading the leading edge and the trailing edge of the document with the butting sensor 11. When the document is transported from the resist section C to the turn section D by driving the pull-out roller 12 and the intermediate roller 14, the transport speed at the resist section C is set higher than the transport speed at the first reading transport section E. Thus, the processing time for sending the document to the first reading conveyance unit E is shortened.

  Control after the leading edge of the document is detected by the reading entrance sensor 15 differs depending on whether the operation mode is the non-stop mode or the stop mode.

  In the non-stop mode, before the leading edge of the document enters the nip portion of the reading entrance roller 16, the reading motor 103 is driven to rotate forward at the same time as deceleration is started in order to make the document conveying speed equal to the reading conveying speed. The reading inlet roller 16, the reading outlet roller 23, and the CIS outlet roller 27 are driven.

  Thereafter, the leading edge of the document is detected by the registration sensor 17 and the first surface (document surface) with respect to the main body control unit 111 at the timing when the leading edge of the document detected by the pulse count of the reading motor 103 reaches the reading position 20. A gate signal indicating an effective image area in the sub-scanning direction is transmitted until the trailing edge of the original passes through the reading position 20.

  On the other hand, in the stop mode, after the leading edge of the document is detected by the reading inlet sensor 15, a predetermined pulse count number is supplied so that a predetermined amount of deflection occurs after the document hits the nip portion of the reading inlet roller 16. After the paper motor 102 is driven, the document is stopped (resist stop), and a registration stop signal is transmitted to the main body control unit 111 via the I / F 107. That is, the position where the reading entrance roller 16 is provided is a stop position where the document stops.

  Subsequently, when a reading start signal is received from the main body control unit 111, the document whose registration has been stopped is transported at an increased speed to reach a predetermined transport speed until the leading edge reaches the reading position 20.

  Thereafter, the leading edge of the document is detected by the registration sensor 17, and at the timing when the leading edge of the document detected by the pulse count of the reading motor 103 reaches the reading position 20, the sub-scanning direction of the first surface with respect to the main body control unit 111 A gate signal indicating an effective image area is transmitted until the trailing edge of the document passes through the reading position 20.

  When the operation mode is the single-sided mode, the controller 100 conveys the document that has passed through the first reading conveyance unit E to the paper discharge unit G via the second reading unit 25. At this time, when the leading edge of the document is detected by the paper discharge sensor 24, the controller 100 drives the paper discharge motor 104 to rotate forward to rotate the paper discharge roller 28 counterclockwise. The controller 100 counts the pulses of the paper discharge motor 104 after the paper discharge sensor 24 detects the leading edge of the original, and the paper discharge motor 104 immediately before the trailing edge of the original comes out of the nip area of the paper discharge roller 28. The driving speed is reduced so that the document discharged onto the paper discharge tray 29 does not jump out.

  As described above, in the stop mode, the document is temporarily stopped by the reading entrance roller 16 when the leading edge is detected by the reading entrance sensor 15, and in the non-stop mode, the document is conveyed without being temporarily stopped. The reading entrance roller 16 constitutes an original conveying member for conveying an original in the present invention.

  When the operation mode is the duplex mode, the controller 100 counts the pulses of the reading motor 103 after the leading edge of the document is detected by the paper discharge sensor 24, and the leading edge of the document reaches the second reading unit 25. At timing, a gate signal indicating an effective image area in the sub-scanning direction is output to the second reading unit 25. The gate signal is continuously output from the second reading unit 25 until the trailing edge of the document comes out.

  The surface of the second reading unit 25 is subjected to an antifouling coating process in order to prevent transfer of foreign matters on the glue attached to the document. The second reading roller 26 is disposed so as to face the second reading unit 25, and when the original passing through the second reading unit 25 is pressed against the second reading unit 25, the floating of the original in the second reading unit 25 is suppressed. At the same time, it also serves as a reference white part for acquiring shading data in the second reading unit 25 and performing shading correction. That is, the second reading roller 26 also serves as a white shading member.

  Next, the operation will be described. The following processes are performed by the controller 100.

  FIG. 5 is a flowchart showing a conveyance process of the automatic document conveyance device according to the embodiment of the present invention.

  As shown in FIG. 5, first, the operation mode is set to unconfirmed for each original (step S1), the timer reset flag is set to 0 (step S2), and the pulse reset flag of the paper feed motor 102 is set to 0. (Step S3), the non-stop mode transition permission flag is set to permitted (Step S4).

  Next, a mode determination process for determining the operation mode is performed (step S5), a transport resumption determination process is performed based on the result of the mode determination process (step S6), and a paper feed transport control process is performed (step S7).

  Next, it is determined whether or not the leading edge of the document reaches the reading position 20 and reading of the document is started and the timer reset flag is 1. If this determination is “Yes”, the process is terminated. If the determination is “No”, the process returns to step S5. Note that the timer reset flag of 1 means that the timer counter T1 has been reset to 0, as will be described later in steps S42 and S43 in FIG. The timer counter T1 is a reference for a document to be fed next.

  FIG. 6 is a flowchart showing the mode determination process of the automatic document feeder according to the embodiment of the present invention.

  As shown in FIG. 6, first, it is determined whether or not the preceding document is stopped (step S11). If it is stopped, the non-stop mode transition permission flag is set to be prohibited (step S16). In step S11, specifically, it is determined whether or not the control for stopping the preceding document against the reading entrance roller 16 is already started, and the control for stopping is started. If it is determined that the document is stopped.

  After step S11, it is determined whether or not the operation mode is unconfirmed (step S12). If the operation mode is unconfirmed, it is determined whether or not a stop mode designation signal is received from the main body control unit 111. (Step S13) If the stop mode designation signal is received, the operation mode is set to the stop mode (Step S17).

  If the stop mode designation signal is not received in step S13, it is confirmed whether or not a reading start signal is received from the main body control unit 111 (step S14). If the reading start signal is received, the operation mode is changed. The non-stop mode is set (step S18).

  If the reading start signal is not received in step S14, it is confirmed whether the non-stop mode transition permission flag is prohibited (step S15). If it is prohibited, the operation mode is set to the stop mode (step S19).

  As described above, in the mode determination process, the operation mode is determined based on the document conveyance status (whether the preceding document is stopped) or the signal (stop mode designation signal, reading start signal) received from the main body control unit 111. Judgment is made.

  FIG. 7 is a flowchart showing a conveyance restart determination process of the automatic document feeder according to the embodiment of the present invention.

  As shown in FIG. 7, first, the timer counter T1 is updated according to the elapsed time since the previous reset to 0 (step S42 in FIG. 8) (step S21), and the document is waiting at the position of the pull-out roller 12 Whether or not the document conveying operation by the pull-out roller 12 has not been resumed (step S22). If this determination is "No", this process is terminated.

  When the determination in step S22 is “Yes”, it is determined whether the target document is the first one in the job, that is, after the document bundle 1 composed of a plurality of documents is set on the document table 2 continuously. It is confirmed whether or not it is the first sheet of a series of work that ends the conveyance operation (operation in the continuous conveyance mode) (step S23). If the determination in step S23 is "Yes", that is, the first sheet, the preceding operation is performed. Since the document does not exist and is not subjected to the restriction condition that the operation cannot be started earlier than Tme shown in FIG. 11 and the restriction condition that the operation cannot be started earlier than Tmb shown in FIG. Then, the pull-out roller 12 and the intermediate roller 14 are driven (step S27).

  If the determination in step S23 is "No", the operation mode is set to the stop mode and the timer counter T1 is set so as to satisfy the delay time required in the stop mode (the above-described constraint condition shown in FIG. 11 is satisfied). Or not, that is, whether or not the stop mode operation is possible (step S24). If the determination in step S24 is "Yes", the paper feed motor 102 Reverse rotation driving is started to drive the pull-out roller 12 and the intermediate roller 14 (step S27). This delay time is determined by the time required for the original to reach the reading entrance roller 16 during the stop mode operation, the basic speed of the original conveyance, the layout of the conveyance path, and the like.

  When the determination in step S24 is “No”, the operation mode is set to the non-stop mode and the delay time required when the timer counter T1 is in the non-stop mode (to satisfy the above-described constraint condition shown in FIG. 12). (Time set in step S25), that is, whether or not the non-stop mode operation is possible (step S25). If the determination in step S25 is "Yes", the paper is fed. The reverse rotation driving of the motor 102 is started to drive the pull-out roller 12 and the intermediate roller 14 (step S27). This delay time is, for example, a document reading interval (document interval L shown in FIG. 12) or a document as a designated document interval notified from the main body control unit 111 of the image forming apparatus main body 60 through the I / F 107 before the start of the conveyance operation. It is determined by the basic speed of conveyance.

  When the determination in step S25 is “No”, the operation mode is still unconfirmed, the timer counter T1 is longer than the necessary delay time in the stop mode, and the timer counter T1 is necessary in the non-stop mode. It is determined whether or not it is longer than the delay time (step S26). If the determination in step S26 is "Yes", the reverse driving of the paper feed motor 102 is started to drive the pull-out roller 12 and the intermediate roller 14 ( If the determination in step S27) and step S26 is "No", this process ends. That is, in step S26, it is determined whether or not the conveyance operation can be resumed regardless of whether the operation mode is the stop mode or the non-stop mode.

  As described above, in the conveyance resumption determination process, it is determined whether or not to resume the conveyance operation of the document that has been abutted against the pull-out roller 12 and is in a standby state according to the conveyance state or the operation mode setting state. It has become. Whether or not the conveyance operation is to be resumed is mainly determined based on the timer counter T1 that is reset to 0 (step S42 in FIG. 8) when a series of processing is executed on the preceding document. Regardless of the stop mode or the stop mode, the relative positional relationship with the preceding document is managed and determined.

  FIG. 8 is a flowchart showing the paper feeding / conveying control process of the automatic document feeder according to the embodiment of the present invention.

  As shown in FIG. 8, first, it is confirmed whether or not a document is waiting at the reading entrance roller 16 (step S31). If this determination is "No", a pulse reset flag of the paper feed motor 102 is obtained. It is confirmed whether or not is 1 (step S32).

  If the determination in step S32 is “No”, it is confirmed whether or not the detection result of the reading entrance sensor 15 has changed from OFF (document non-detection state) to ON (document detection state) from the previous time (step S33).

  If the determination in step S33 is “Yes”, the drive pulse of the paper feed motor 102 is reset to 0 (step S34), and the pulse reset flag of the paper feed motor 102 is set to 1 (step S35). On the other hand, if the determination in step S33 is "No", the process proceeds to step S40.

  Following step S35, it is confirmed whether the operation mode is set to the stop mode and the number of drive pulses of the paper feed motor 102 exceeds the stop pulse in the stop mode (step S36). If “Yes”, the stop of the paper feed motor 102 is controlled to start the abutting of the original against the reading entrance roller 16 (step S38), and the transition permission flag to the non-stop mode is set to be prohibited (step S38). Step S39). The stop pulse in the stop mode in step S36 is the stop of the document at the transport distance obtained by adding a predetermined abutting amount to the transport path length from the reading entrance sensor 15 to the reading entrance roller 16 and the current transport speed. It is set in consideration of the distance required to do.

  If the determination in step S36 is "No", it is confirmed whether the operation mode is set to the non-stop mode and whether the number of drive pulses of the paper feed motor 102 exceeds the stop pulse in the non-stop mode. (Step S37) If the determination in Step S37 is "Yes", the paper feed motor 102 is decelerated to the basic transport speed (Step S44). The stop pulse in the non-stop mode in step S37 takes into account the length of the conveyance path from the reading inlet sensor 15 to the reading inlet roller 16 and the distance necessary for the deceleration control from the current conveying speed to the basic conveying speed. Is set so that the deceleration is completed when the leading edge of the ink reaches the reading entrance roller 16. However, by intentionally delaying the deceleration start timing, the original may be abutted against the reading entrance roller 16 due to a difference in the motor rotation speed and controlled to be bent.

  After steps S37 and S44, it is confirmed whether or not the timer reset flag is 1 (step S40). If this determination is “No”, that is, if the timer reset flag remains 0, the reading inlet sensor 15 is turned on. It is confirmed whether or not there has been a change from the previous (document detection state) to OFF (document non-detection state) (step S41).

  If the determination in step S41 is "Yes", that is, if the reading entrance sensor 15 has changed from ON (document detection state) to OFF (document non-detection state) from the previous time, the timer counter T1 serving as a reference for the next document conveyance restart timing Is reset to 0 (step S42), the timer reset flag is set to 1 (step S43), and this process is terminated.

  If the determination in step S31 is "Yes", that is, if the document is in the stop standby state at the reading entrance roller 16, it is confirmed whether or not a reading start signal has been received from the main body control unit 111 (step S45). If so, the reverse rotation drive of the paper feed motor 102 is started and the conveyance to the reading position 20 is resumed (step S46).

  As described above, in the paper feed conveyance control process, stop and deceleration control of the paper feed motor 102 is performed based on the operation mode set in the mode determination process, and the timer counter T1 serving as a reference for the conveyance timing for the next document. The reset operation (whether or not to reset) is controlled.

  In the mode determination process described with reference to FIG. 6, based on the document conveyance status (whether the preceding document is stopped) or a signal received from the main body control unit 111 (stop mode designation signal, reading start signal). Although the operation mode is determined, as will be described later with reference to FIG. 9, the automatic document feeder 50 alone determines whether to enter the stop mode without receiving a stop mode designation signal or a reading start signal. You may do it.

  FIG. 9 is a flowchart showing the second mode determination process of the automatic document feeder according to the embodiment of the present invention. When the second mode determination process is executed instead of the mode determination process, the automatic document feeder 50 alone determines whether to enter the stop mode without receiving the stop mode designation signal.

  As shown in FIG. 9, first, it is confirmed whether or not the preceding document has already started the stop control for the abutting control at the reading entrance roller 16 (step S51). The permission flag is set to prohibit (step S52).

  Next, it is determined whether or not the operation mode is unconfirmed (step S53). If the operation mode is unconfirmed, the timer counter T2 that is the time during which the non-stop mode continues is updated (step S54). If the operation mode is not yet determined, this process is terminated.

  Next, it is determined whether or not the timer counter T2 is equal to or longer than a preset non-stop mode maximum duration (step S55). If this determination is "Yes", the operation mode is set to the stop mode (step S55). S59).

  When the determination in step S55 is “No”, it is determined whether or not a stop mode designation signal is received from the main body control unit 111 (step S56). If the stop mode designation signal is received, the operation mode is stopped. The mode is set (step S59).

  If the stop mode designation signal is not received in step S56, it is confirmed whether or not a reading start signal is received from the main body control unit 111 (step S57). If the reading start signal is received, the operation mode is changed. The non-stop mode is set (step S60).

  If the reading start signal is not received in step S57, it is checked whether or not the non-stop mode transition permission flag is prohibited (step S58). If the reading start signal is prohibited in step S58, the operation mode is set to the stop mode. (Step S61), the timer counter T2 is reset to 0 (Step S62), and this process ends.

  As described above, in the second mode determination process, when it is determined in step S55 that the timer counter T2 updated in step S54 is larger than the predetermined non-stop mode maximum duration, the process proceeds to step S59 and the operation mode is changed. Set to stop mode. The timer counter T2 is reset to 0 in step S62 when the operation mode is set to the stop mode in step S59 or step S61. Note that the non-stop mode maximum duration time is set in advance in consideration of, for example, the attenuation characteristic of the light amount 81a provided on the image forming apparatus main body 60 side.

  FIG. 10 is a diagram showing an operation result of the automatic document feeder according to the embodiment of the present invention. In FIG. 10, an operation result related to the operation mode and productivity set according to the timing at which the reading start signal is received from the image forming apparatus main body 60 is shown in the lower part of FIG. The operation mode set according to the timing at which the stop mode designation signal is received from the forming apparatus main body 60 and the operation result related to the productivity are indicated by the seventh stage item G, and the difference in the operation result from the conventional automatic document feeder is shown. This will be explained in contrast. Productivity is the number of documents that can be processed per unit time.

  As shown in item F in FIG. 10, when the image forming apparatus main body 60 side as an image reading apparatus including the image reading unit 81 intentionally sets the automatic document feeder 50 to the non-stop mode operation, Tb is set. If the image forming apparatus main body 60 transmits a reading start signal to the automatic document feeder 50 within a period indicated by F1 with the indicated timing as an end point, the automatic document feeder 50 can operate in the non-stop mode. The document transport operation can be resumed from the point in time, which is optimal in terms of productivity.

  If the image forming apparatus main body 60 transmits a reading start signal to the automatic document feeder 50 within the period indicated by F2 with the timing indicated by Tc as the end point, the automatic document feeder 50 is not in time for F1. , The productivity is slightly inferior to when the reading start signal is received in the period indicated by F1, but the operation in the non-stop mode, which is more productive than the stop mode, can be performed and is delayed from the end of the period indicated by F1. It can be suppressed to a decrease in productivity only by time.

  If the reading start signal is further delayed and the image forming apparatus main body 60 transmits a reading start signal to the automatic document feeder 50 within the period indicated by F3, the automatic document feeder 50 operates in the stop mode. Although the productivity is greatly reduced, the operation result of the present embodiment indicated by item F is the non-stop mode operation and the stop mode compared to the item D which is the operation result of the conventional automatic document feeder. The boundary at which the operation is switched is set at a timing with a margin.

  On the other hand, as shown in item G, the automatic document feeder 50 is set to operate in the stop mode with the intention that the image forming apparatus main body 60 side as an image reading apparatus including the image reading unit 81 spends time by shading movement or the like. In this case, if the image forming apparatus main body 60 transmits a stop mode designation signal to the automatic document feeder 50 within the period indicated by G1, the operation of the stop mode can be started at an earlier timing than in the prior art. No. 50 can restart the document conveying operation from the point of time when the operation in the stop mode becomes possible, and is the optimum operation in terms of productivity.

  If the image forming apparatus main body 60 transmits a stop mode designation signal to the automatic document feeder 50 within the period indicated by G2, even if the time is not in time for G1, the automatic document feeder 50 will stop the stop mode during the period indicated by G1. Although the operation in the stop mode, which is slightly inferior to the time when the designation signal is received, is performed, it is possible to suppress the productivity drop only by the time delayed from the end of the period indicated by G1.

  If transmission / reception of the stop mode designation signal is further delayed and transmission / reception of the stop mode designation signal is performed between the image forming apparatus main body 60 and the automatic document feeder 50 within the period indicated by G3, the stop mode designation signal is stopped. The effect of receiving or not receiving the mode designation signal is lost, and it is inevitable that the productivity will be significantly lower than intended.

  Thus, in the conventional automatic document feeder, as shown in item D, when a reading start signal is received from the image forming apparatus main body after Ta, the stop which is inferior in productivity from the non-stop mode which is excellent in productivity. In the automatic document feeder 50 according to the present embodiment, as shown in item F, a read start signal is output from the image forming apparatus main body 60 after Tc, which is a timing later than Ta. When received, the non-stop mode is changed to the stop mode, so that a control margin is generated by the time difference between Ta and Tc, and the operation for productivity is optimized. Further, in the automatic document feeder 50 according to the present embodiment, as shown in the item G, the stop mode designation signal is received before the timing indicated by Ta, so that it is optimum in productivity even in the operation in the stop mode. Control can be performed.

  As described above, the automatic document feeder 50 according to the present embodiment can be mounted on the image forming apparatus main body 60 capable of reading the conveyed document at the fixed reading position 20, and each document is one by one. In the automatic document feeder 50 that conveys the document to the reading position 20, a reading inlet sensor 15 that detects that the document has reached a stop position (position of the reading inlet roller 16) near the upstream of the reading position 20, and the document reading position 20. When the reading entrance sensor 15 detects that the document has reached the stop position when the document is transported to the stop position, the transport operation is stopped and the document is stopped at the stop position, and then the transport operation is resumed to restart the read position 20. The operation mode is set to any one of a stop mode for conveying the document to the reading position and a non-stop mode for conveying the document to the reading position 20 without stopping at the stop position. When a predetermined condition is satisfied before the judgment deadline for determining whether to set the stop mode or non-stop mode, the operation mode is set to the stop mode, and the conveyance of the document is controlled based on the set operation mode. The controller 100 is provided.

  Therefore, it is determined whether or not a predetermined condition for setting the stop mode is satisfied, that is, whether or not the stop mode designation signal is received or whether the value of the timer counter T2 is equal to or longer than the maximum non-stop mode duration. Is performed before the judgment deadline, and when this condition is satisfied, the operation mode is set to the stop mode, so that optimal control in terms of productivity can be performed in both the stop mode and the non-stop mode. Therefore, the operation mode can be set with a margin with respect to variations occurring in the information that is the basis for the determination. Therefore, even when various conditions such as the mechanical mechanism and the basic conveyance speed change, productivity can be stably secured.

  In addition, the automatic document feeder 50 according to the present embodiment is configured so that the controller 100 causes the controller 100 to select one of the plurality of documents when the conveyance mode is set to the continuous conveyance mode in which a plurality of documents are continuously conveyed to the reading position 20. The document is conveyed so that the distance between the preceding document and the succeeding document is as narrow as possible in the mechanism.

  For this reason, since the interval between the documents fed continuously is controlled to be as narrow as possible in structure, it is possible to stably achieve high productivity.

  The automatic document feeder 50 according to the present embodiment includes an I / F 107 that receives a stop mode designation signal transmitted from the image forming apparatus main body 60 when the image forming apparatus main body 60 is readable. If the operation mode is indeterminate and a stop mode designation signal is received before the judgment deadline, the operation mode is set to the stop mode and the document is transported as soon as the operation becomes possible. Resume operation.

  Therefore, the operation is performed in cooperation with the image forming apparatus main body 60, and the conveyance operation when intentionally performing the operation in the stop mode is optimized as the entire system, and can be performed quickly and stably without waste. .

  The automatic document feeder 50 according to the present embodiment includes an I / F 107 that receives a reading start signal transmitted from the image forming apparatus main body 60 when the image forming apparatus main body 60 is readable. When the reading mode is received before the judgment deadline when the operation mode is indeterminate, the operation mode is set to the non-stop mode, and the document is transported as soon as the operation in the non-stop mode becomes possible. Resume operation.

  Therefore, the operation is performed in cooperation with the image forming apparatus main body 60, and the conveyance operation when intentionally performing the operation in the non-stop mode can be optimized as the entire system, and can be performed quickly and stably without waste. Become.

  Further, in the automatic document feeder 50 according to the present embodiment, the controller 100 is in a state where the operation mode is unconfirmed, the operation in the stop mode is possible, and the operation in the non-stop mode is performed. As soon as it becomes possible, the document transport operation is resumed.

  For this reason, even if the operation mode is indeterminate, unnecessary when there is a delay in transmission or reception of the stop mode specification signal or reading start signal by performing the transport operation as soon as there is no problem in operation. Therefore, it is possible to avoid delaying the conveyance control.

  Further, in the automatic document feeder 50 according to the present embodiment, the determination deadline is the same timing as the latest timing at which the operation mode can be set to the non-stop mode or the latest timing in terms of mechanism and control. The timing is earlier.

  For this reason, by making the transition to the non-stop mode operation as slow as possible in terms of mechanism and control, it is possible to avoid the occurrence of a large delay in productivity even if there are some variations in control. be able to.

  Further, in the automatic document feeder 50 according to the present embodiment, when the conveyance mode is set to the continuous conveyance mode, the controller 100 sets the operation mode to the non-stop mode or the stop mode independently for each document. To do.

  For this reason, since the setting of the non-stop mode and the stop mode can be set independently for each document, it is possible to diversify the operations that can be performed when continuously reading the document.

  Further, the automatic document feeder 50 according to the present embodiment is provided with a reading entrance roller 16 provided at a stop position and against which a document to be stopped hits, and when the controller 100 is set to the stop mode, The original is stopped in a state where the original is abutted against the reading entrance roller 16.

  For this reason, when the document being conveyed is abutted against the reading entrance roller 16 during the operation in the stop mode, the skew of the document generated during the document conveyance can be corrected and the conveyance quality can be improved.

  In the automatic document feeder 50 according to the present embodiment, the reading entrance roller 16 also serves as a document conveying member that conveys the document.

  For this reason, the number of parts can be reduced and the configuration can be simplified.

  In the automatic document feeder 50 according to the present embodiment, the controller 100 measures the time during which the non-stop mode is continued as the timer counter T2, and the timer counter T2 is set to the non-stop mode maximum before the determination time limit. When it is longer than the duration, the operation mode is set to the stop mode, and the document transport operation is resumed as soon as the operation in the stop mode becomes possible.

  Therefore, by counting the time during which the non-stop mode is continuously executed as the value of the timer counter T2, it is possible to determine whether or not the automatic document feeder 50 alone shifts to the stop mode. Thus, an optimum operation can be performed without extra communication with the image forming apparatus main body 60.

  Further, in the automatic document feeder 50 according to the present embodiment, when the controller 100 is set to the non-stop mode and the conveyance mode is set to the continuous conveyance mode, the document interval is determined in advance. Documents are conveyed so that the specified document interval is reached.

  For this reason, by setting the document interval at the time of setting the continuous conveyance mode to the specified document interval, a stable conveyance operation can be performed.

  In addition, the automatic document feeder 50 according to the present embodiment includes an I / F 107 that receives a specified document interval from the image forming apparatus main body 60, and the controller 100 specifies a specified document interval that is received by the I / F 107. The original is conveyed so that

  For this reason, since the document interval is controlled to the designated document interval designated by the image forming apparatus main body 60, it is possible to perform a stable conveyance operation corresponding to various operations and situations of the image forming apparatus main body 60.

  In addition, since the image forming apparatus main body 60 as an image reading apparatus includes the automatic document feeder 50, the system as a whole can stably operate with high productivity in response to various situations and control requirements. Can be performed.

  As described above, the automatic document conveying device and the image reading device according to the present invention can stably ensure productivity even if various conditions such as a mechanical mechanism and a basic conveying speed change. And is useful as a sheet-through automatic document feeder and an image reader that conveys a document to a fixed reading position.

1 is a schematic configuration diagram of an automatic document feeder according to an embodiment of the present invention and an image reading apparatus including the automatic document feeder. 1 is a configuration diagram of an automatic document feeder according to an embodiment of the present invention. FIG. 2 is a block diagram of a control system of the automatic document feeder according to the embodiment of the present invention. FIG. 1 is a block diagram illustrating a configuration of an image reading unit of an automatic document feeder according to an embodiment of the present invention. FIG. It is a flowchart which shows the conveyance process of the automatic document conveying apparatus which concerns on one embodiment of this invention. It is a flowchart which shows the mode determination process of the automatic document feeder which concerns on one embodiment of this invention. It is a flowchart which shows the conveyance resumption determination process of the automatic document feeder which concerns on one embodiment of this invention. It is a flowchart which shows the paper feeding conveyance control process of the automatic document conveying apparatus which concerns on one embodiment of this invention. It is a flowchart which shows the mode determination 2nd process of the automatic document feeder which concerns on one embodiment of this invention. It is a figure which shows the operation result of the automatic document feeder which concerns on one embodiment of this invention. 10 is a timing chart showing a transport operation in a stop mode of a conventional automatic document feeder. 10 is a timing chart showing a conveying operation in a non-stop mode of a conventional automatic document feeder. It is a figure which shows the operation result of the conventional automatic document feeder.

Explanation of symbols

15 Reading inlet sensor (detection means)
16 Reading entrance roller (abutting member, document conveying member)
20 reading position 50 automatic document feeder 60 image forming apparatus main body (image reading apparatus)
70 Image forming apparatus 100 Controller (Operation mode setting means, stop mode setting means, non-stop mode setting means, transfer control means, transfer mode setting means, time measuring means)
102 Feeding motor 103 Reading motor 107 I / F (stop mode designation signal receiving means, reading start signal receiving means, designated document interval receiving means)

Claims (13)

In an automatic document feeder that can be mounted on an image reading apparatus that can read a document to be conveyed at a fixed reading position, and that conveys the documents one by one to the reading position,
Detecting means for detecting that the document has reached a stop position near the upstream of the reading position;
When transporting the document to the reading position, if the detection means detects that the document has reached the stop position, the transport operation is stopped and the document is stopped at the stop position, and then the transport operation is performed. An operation mode setting means for setting the operation mode to any one of a stop mode that resumes and transports the document to the reading position and a non-stop mode that transports the document to the reading position without stopping at the stop position;
The operation mode is set to the stop mode by the operation mode setting means when a predetermined condition is satisfied before a determination time limit for determining whether the operation mode is set to the stop mode or the non-stop mode. Stop mode setting means,
An automatic document conveying apparatus comprising: a conveyance control unit that controls conveyance of a document based on an operation mode set by the operation mode setting unit. A conveyance mode setting unit that sets a conveyance mode to a continuous conveyance mode in which a plurality of documents are continuously conveyed to the reading position by the conveyance control unit;
When the transport mode is set to the continuous transport mode, the transport control means sets the document so that the interval between the preceding document and the succeeding document is the smallest possible in the mechanism. The automatic document feeder according to claim 1, wherein the automatic document feeder is conveyed. A stop mode designation signal receiving means for receiving a stop mode designation signal transmitted by the image reading apparatus when the image reading apparatus is readable;
When the stop mode setting means receives the stop mode designation signal by the stop mode designation signal receiving means before the determination deadline in a state in which the operation mode is indeterminate, the operation mode setting means causes the Set the operation mode to the stop mode,
3. The automatic document conveying apparatus according to claim 2, wherein the conveyance control unit resumes the document conveying operation as soon as the operation in the stop mode is possible. A reading start signal receiving means for receiving a reading start signal transmitted by the image reading apparatus when the image reading apparatus is readable;
If the reading start signal is received by the reading start signal receiving means before the determination deadline in a state where the operation mode is indefinite, the operation mode is set to the non-stop mode by the operation mode setting means. Non-stop mode setting means for performing,
4. The automatic document conveyance device according to claim 1, wherein the conveyance control unit resumes the document conveyance operation as soon as the operation in the non-stop mode is enabled.   As soon as the transport control means is in a state in which the operation mode is unconfirmed, is in a state in which the operation in the stop mode is possible, and is in a state in which the operation in the non-stop mode is possible, the transport operation of the document 5. The automatic document feeder according to claim 1, wherein the automatic document feeder is resumed.   The determination time limit is the same timing as the latest timing at which the operation mode can be set to the non-stop mode in terms of mechanism and control, or an earlier timing than the latest timing. The automatic document feeder according to any one of claims 1 to 5.   The operation mode setting means sets the operation mode to the non-stop mode or the stop mode independently for each document when the transport mode is set to the continuous transport mode. The automatic document feeder according to any one of claims 1 to 6. Provided with an abutting member provided at the stop position, against which the document to be stopped abuts,
9. The conveyance control unit according to claim 1, wherein when the operation mode is set to the stop mode, the conveyance control unit stops the document in a state where the document is abutted against the abutting member. The automatic document feeder according to any one of the above.   9. The automatic document feeder according to claim 8, wherein the abutting member also serves as a document conveying member that conveys a document. Comprising time measuring means for measuring the time during which the non-stop mode continues,
The stop mode setting means sets the operation mode to the stop mode by the operation mode setting means when the time counted by the time measuring means is a predetermined time or more before the determination deadline,
10. The automatic document conveyance device according to claim 1, wherein the conveyance control unit resumes the document conveyance operation as soon as the operation in the stop mode becomes possible.   When the operation mode is set to the non-stop mode and the conveyance mode is set to the continuous conveyance mode, the conveyance control unit sets the document so that the document interval becomes a predetermined designated document interval. The automatic document conveying device according to claim 2, wherein the automatic document conveying device conveys the original. A designated document interval receiving means for receiving the designated document interval from the image reading device;
12. The automatic document conveyance device according to claim 11, wherein the conveyance control unit conveys the document so that the document interval is equal to the designated document interval received by the designated document interval reception unit.   An image reading apparatus comprising the automatic document feeder according to any one of claims 1 to 12.

Images