JP2005060036A - Automatic document feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic document feeder capable of rapidly reverse-reading a double-sided document by omitting paper delivery completion wait time of a preceding document and paper delivery operation start wait time of an inverted document after completion of paper delivery. <P>SOLUTION: When two sheets of documents, that are, the both side read document and a surface read document are disposed on a contact glass 18 parallel with each other in a document both side reading mode, this automatic document feeder 1 positions a both side read document and a surface read document on the contact glass 18 parallel with each other at an interval for carrying the tip of the surface read document to a position where a discharge sheet inlet sensor 16 detects the document immediately after the discharge of the both side read document is completed when the discharge operation of the both side read document and the reversal operation of the surface read document are continuously performed. Accordingly, the document can be prevented from being jammed or damaged, and the carrying time of the double-sided document can be shortened to increase a treating speed in both side reading by omitting a wasteful time from the completion of discharge of the both side read document to the start of reversal of the surface read document. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an automatic document feeder, and more particularly, an automatic document feeder that quickly performs reverse reading of a double-sided document without a waiting time for completion of discharging and a waiting time for starting the operation of discharging a reversed document after completion of discharging. Relates to the device.

  2. Description of the Related Art Conventionally, in an image reading apparatus such as a copying machine, a facsimile machine, and a scanner apparatus, an automatic document conveying device that automatically conveys a document to a document reading position of the image reading device is mounted in order to improve document reading efficiency. It has become to.

  Such an automatic document feeder separates a plurality of documents set on a document table one by one and sequentially conveys them with a predetermined gap between them, in order to improve copy efficiency. In order to narrow the gap between the original sheets, the leading edge of the next original is conventionally fed to a predetermined first-out position.

  As a conventional technique for performing the advance delivery of such a document, for example, during the copying of the first document, the first delivery of the second document from the document tray is started and then the third document on the document tray is started. When the presence of a document is detected, the first copy paper is fed out to the third document, and the first feed in a copying machine that detects the presence of the third document at least at the start of feeding the copy paper. There is a paper method (see Patent Document 1).

  In other words, this prior art prevents unnecessary first-out feeding by not performing first-out feeding when the third original is extracted before feeding the copy paper to the third original. Yes.

  However, the above technique is a technique for reading only one side of an original. When reading a double-sided original, it is necessary to invert the original that has been read on one side and transport it again onto the contact glass.

  Therefore, the applicant first separated a plurality of double-sided documents placed on the document placing table one by one upstream from one end side of the contact glass and fed them to the reading position on the one end side on the contact glass. A separation feeding unit for feeding, a paper discharge unit for discharging a double-sided original after double-sided reading from the contact glass downstream of the other end of the contact glass, and a double-sided original fed separately is conveyed on the contact glass An automatic document feeder including a transport unit, wherein the transport unit transports the first double-sided document after double-sided scanning from the reading position toward the paper discharge unit, and the separation paper feed unit. And an automatic control unit for controlling the second double-sided original to be separated and fed to the reading position at a predetermined interval, and thereafter the first double-sided original is discharged from the contact glass by the paper discharge unit. Document transport equipment Proposes (see Patent Document 2).

  That is, in this prior art, both the double-sided scanned original and the front-side scanned original are arranged at predetermined intervals on the contact glass, and after the double-sided scanned original is discharged, the original reversing operation of the front-side scanned original is performed. To reduce the time required for double-sided document scanning.

JP-A-5-105273

JP 2003-12241 A

  However, in the prior art described in Patent Document 2, depending on the document interval, the reversed document arrives at the discharge unit before the discharge of the discharged document is completed, and there is a difference between the discharge speed and the conveyance speed. Therefore, there is a possibility that the original is involved in both drive systems, and the original is jammed or damaged.

  Accordingly, the invention described in claim 1 separates a plurality of documents placed on the document table one by one by the document feeding means and conveys them to the document reading position on the contact glass. After the reading of the front surface of the document at the reading position is completed, the document reversing means reverses the front and back surfaces of the document, conveys the back surface to the document reading position, and has been read by the paper discharge means that operates by the rotation operation of the paper discharge motor. The original on the contact glass is transported to the paper ejecting means or transported to the document reading position by the transport means that operates by rotating the transport motor. Means for detecting the presence or absence of a document at a predetermined position between the contact glass and the paper discharge means, and the above-described means are operated based on an instruction from the main body control means of the main body device. Documents scanned on both sides on glass When the two-sided scanned originals are juxtaposed and the two-sided scanned original is discharged and the front-side reversed document is continuously operated, the two-sided scanned original is discharged at the same time as Prevents jamming and breakage of originals by placing the two-sided scanned original and the front-side scanned original on the contact glass at the distance between the originals conveyed to the position detected by the paper exit entrance original detection means. On the other hand, automatic document transport that eliminates wasted time from the completion of paper discharge of a duplex scanned document to the start of reversing of a front scanned document, shortens the transport time of a duplex document, and improves the processing speed during duplex scanning. The object is to provide a device.

  According to a second aspect of the present invention, there is provided a document conveyance distance measuring unit that measures the amount of movement of the document on the contact glass based on the number of steps of the conveyance motor, and the document reading position is in the direction of paper discharge by the conveyance unit of the double-sided scanned document When the number of steps of the conveyance motor measured by the document conveyance distance measuring unit reaches a predetermined value set in advance from the start of the conveyance operation, the document feeding unit starts feeding the next document on the document table. Thus, by generating the document interval, the document interval is accurately controlled to reliably prevent the occurrence of jamming and breakage of the document, and from the completion of the discharge of the double-sided scanned document to the start of the reverse of the front-side scanned document. It is an object of the present invention to provide an automatic document conveying apparatus that can appropriately eliminate the wasted time between the two sheets, further reduce the conveying time of the two-sided document, and further improve the processing speed at the time of two-sided reading.

  According to the third aspect of the present invention, when the front side reading document is turned upside down, the conveying speed of the front side reading document to the discharge entrance original detecting means is made equal to the discharging speed of the discharging motor. An object of the present invention is to provide an automatic document feeder that more appropriately prevents jamming and breakage of a document.

  According to a fourth aspect of the present invention, the paper discharge means includes a plurality of rollers that are driven to rotate by a paper discharge motor and are arranged along the document transport direction, and of the plurality of rollers, A clutch for turning on / off the connection with the paper discharge motor, and the paper discharge operation of the paper output by the paper discharge means in a state where the connection between the uppermost roller and the paper discharge motor is turned off by the clutch. The discharge motor is rotated by a predetermined amount slower than the conveyance speed of the conveyance motor. After the discharge of the discharged document is completed, the rotation speed of the discharge motor is increased so that the discharge speed of the discharge motor is increased. When the conveyance speed by the conveyance motor is reached, the connection between the uppermost roller and the discharge motor is turned on by the clutch, and the surface reading document to be reversed is conveyed to the document reversing means to perform the reversing operation. Paper discharge motor And its object is to provide an automatic document feeder to further reliably prevent the occurrence of the document jam or damage due to a difference in the document transportation speed of the conveying motor.

  An automatic document feeder according to a first aspect of the present invention is mounted on a main body device that reads an image of a document stopped at a document reading position by moving an image reading means, and reads a plurality of documents placed on a document table. A document feeding unit that separates the sheets one by one and conveys them to the document reading position on the contact glass, and after the reading of the front surface of the document at the document reading position is completed, the front and back surfaces of the document are reversed to read the document back The document reversing means for transporting to the position, the paper discharge means for operating the rotating operation of the paper discharge motor to discharge the read document or transporting it to the document reversing means, and the contact motor operating for the rotation operation of the transport motor. A transport unit that transports a document on the glass to the discharge unit or the document reading position; and a discharge entrance document detection unit that detects the presence or absence of the document at a predetermined position between the contact glass and the discharge unit. When, And each unit operates based on an instruction from a main body control unit of the main body apparatus, and two originals, a double-sided scanned original and a front-side scanned original, can be juxtaposed on the contact glass in a double-sided scanning mode. An automatic document feeder, wherein the two-sided scanned document and the front-side scanned document are placed side by side on the contact glass in the document duplex scanning mode; When the document reversing operation is continuously performed, the discharge of the double-sided scanned document is completed, and at the same time, the leading edge of the front-side scanned document is conveyed at a position detected by the discharge entrance document detection means, The above object is achieved by juxtaposing the double-sided scanned document and the front-side scanned document on the contact glass.

  In this case, for example, as described in claim 2, the automatic document feeder includes a document conveyance distance measuring unit that measures a document movement amount on the contact glass based on the number of steps of the conveyance motor, The number of steps of the conveying motor measured by the document conveying distance measuring unit reaches a predetermined value from the start of the conveying operation of the duplex reading document at the document reading position in the paper discharge direction by the conveying unit. At this point, the document interval may be generated by starting the feeding of the next document on the document table by the document feeding means.

  Further, for example, according to a third aspect of the present invention, the automatic document feeder is configured so that the conveyance motor feeds the front-side scanned document to the discharge entrance document detection means during the front / back reversing operation of the front-side scanned document. And the paper discharge speed by the paper discharge motor may be the same speed.

  Further, for example, according to a fourth aspect of the present invention, the automatic document feeder includes a plurality of rollers in which the paper discharge means is rotationally driven by the paper discharge motor and is disposed along the document transport direction. A clutch for turning on / off the connection of the uppermost roller in the document transport direction with the discharge motor, and the discharge operation of the discharged document by the discharge unit is performed by the clutch. With the connection between the most upstream roller and the paper discharge motor turned off, the paper discharge motor was rotated by a predetermined amount slower than the transport speed by the transport motor, and the discharge of the discharged document was completed. Thereafter, when the rotational speed of the paper discharge motor is increased and the paper discharge speed of the paper discharge motor reaches the transport speed of the transport motor, the clutch connects the uppermost roller and the paper discharge motor. The turn on, the surface document reading of the reversing subject may be one to perform the reversing operation is conveyed to the document reversing means.

  According to the automatic document feeder of the invention described in claim 1, a plurality of documents placed on the document table are separated one by one by the document feeding means and conveyed to the document reading position on the contact glass. Then, after the reading of the front surface of the document at the document reading position is completed, the document reversing unit reverses the front and back surfaces of the document and conveys the back surface to the document reading position, and the sheet discharge motor operates by the rotation operation of the sheet discharge motor. Means for conveying the read document to the paper discharge or document reversing means, and transporting the document on the contact glass to the paper discharge means or to the document reading position by the transport means operated by the rotation operation of the transport motor, The discharge entrance original detection means detects the presence or absence of a document at a predetermined position between the contact glass and the discharge means, and the respective means operate based on an instruction from the main body control means of the main body device. On contact glass in scan mode When the two-sided scanned document and the front-side scanned document are juxtaposed, when the two-sided scanned document discharge operation and the front-side scanned document reversal operation are continuously performed, the two-sided scanned document is discharged. At the same time, the front-side scanned document is placed on the contact glass side by side with the distance between the documents that are transported to the position detected by the paper exit entrance document detection means. Can be prevented, and the wasted time from the completion of the discharge of the double-sided scanned document to the start of reversal of the front-side scanned document can be eliminated, and the double-sided document transport time can be shortened and double-sided scanning is performed. The processing speed at the time can be improved.

  According to the automatic document conveying apparatus of the second aspect of the present invention, the document conveying distance measuring means for measuring the document moving amount on the contact glass based on the number of steps of the conveying motor is provided, and the double-sided scanned document at the document reading position is provided. When the number of steps of the conveying motor measured by the document conveying distance measuring unit reaches a predetermined value from the start of the conveying operation in the paper discharge direction by the conveying unit, the next on the document table by the document feeding unit Since the document interval is generated by starting the document feeding, it is possible to accurately control the document interval to reliably prevent the occurrence of jamming or breakage of the document, and The wasteful time from the completion of paper discharge to the start of reversing of the front-side scanned document can be omitted more appropriately, the conveyance time for double-sided documents is further shortened, and the processing speed for duplex scanning is further improved. Door can be.

  According to the automatic document feeder of the invention described in claim 3, when the front side reading document is turned upside down, the feeding speed of the front side reading document by the feeding motor to the discharge entrance document detecting means and the discharging speed by the paper discharging motor. Are set to the same speed, so that jamming and breakage of the original can be more appropriately prevented.

  According to the automatic document feeder of the invention described in claim 4, the paper discharge means is a plurality of rollers that are rotationally driven by a paper discharge motor and arranged along the document transport direction, and of the plurality of rollers, A clutch for turning on / off the connection with the discharge motor of the uppermost roller in the conveyance direction, and the discharge operation of the discharged document by the discharge unit between the uppermost roller and the discharge motor by the clutch. With the connection turned off, the discharge motor is rotated by a predetermined amount slower than the conveyance speed of the conveyance motor. After the discharge of the discharged document is completed, the rotation speed of the discharge motor is increased and the discharge motor is increased. When the paper discharge speed by the paper motor reaches the conveyance speed by the conveyance motor, the clutch is turned on by the clutch to connect the uppermost roller and the paper discharge motor, and the front side scanned original to be turned upside down is conveyed to the original reversing means and reversed. Do the action Because there can be prevented the occurrence of the document jam or damage due to a difference in the document transportation speed between the discharge motor and the conveying motor more reliably.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, since the Example described below is a suitable Example of this invention, various technically preferable restrictions are attached | subjected, However, The scope of the present invention limits this invention especially in the following description. As long as there is no description of the effect, it is not restricted to these aspects.

  1 to 16 are diagrams showing an embodiment of an automatic document feeder of the present invention. FIG. 1 is a schematic front view of an automatic document feeder 1 to which an embodiment of the automatic document feeder of the present invention is applied. It is a block diagram.

  In FIG. 1, an automatic document feeder 1 includes a paper feed mechanism 3, a paper feed roller 4, a transport unit 5, a paper discharge roller 6, a double-side claw 7, a switchback claw 8, a switchback roller 9, and a housing 2. A switchback path 10, a paper discharge path 11, a paper discharge outlet roller 12, a document set sensor 13, a pullout sensor 14, a registration sensor 15, a paper discharge inlet sensor 16, a paper discharge outlet sensor 17, and a switchback sensor 18 are accommodated. A contact glass 19 is provided at the bottom of the housing 2. In the automatic document feeder 1, a paper discharge tray 20 is formed at the top of the housing 2, and a document tray (original table) 21 is provided above the paper discharge tray 20.

  The automatic document feeder 1 is mounted on an image reading device as a main device such as an electrophotographic copying machine, and an image reading unit of the image reading device is disposed below the contact glass 19. The image reading unit of the image reading device irradiates the original conveyed to the original reading position on the contact glass 19 with reading light from a light source (not shown), and photoelectrically reflects the reflected light including the image information of the original reflected by the original. The image of the original is read by performing photoelectric conversion with the conversion element.

  As shown in FIG. 2, the automatic document feeder 1 has a circuit block configuration. The document set sensor 13 (not shown in FIG. 2), a pull-out sensor 14, a registration sensor 15, a paper discharge inlet sensor 16, In addition to a discharge exit sensor 17 and the like, a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, an engine I / O 104, a main body I / F 105, a calling motor 106, A paper feed motor 107, a conveyance motor 108, a paper discharge motor 109, a switchback claw solenoid 110, a double-side claw solenoid 111, a paper discharge clutch 112, and the like are provided. Are connected by a bus 113. The operation unit 201 of the image reading apparatus main body is connected to the main body I / F 105, and the main body I / F 105 notifies the CPU 101 of the operation content of the operation unit 201 via the bus 113. The operation information of the collected automatic document feeder 1 is notified to the operation unit 201 as necessary.

  The engine I / O 104 is connected to the document set sensor 13 (not shown) and the pull-out sensor 14 to the paper discharge clutch 112. The engine I / O 104 is connected between the CPU 101 and the respective parts via the bus 113. Send and receive information.

  In the automatic document feeder 1, the CPU 101 controls each part of the automatic document feeder 1 while using the RAM 103 as a work memory based on a program in the ROM 102 to perform processing as the automatic document feeder 1 and will be described later. A conveyance control process, particularly a double-sided document conveyance control process is executed.

  In the automatic document feeder 1, a plurality of documents are placed on the document tray 21, the document set sensor 13 detects the documents placed on the document tray 21, and is sent to the CPU 101 via the engine I / O 104. Output.

  In the paper feed mechanism (document feed means) 3, when the calling motor 106, which is a stepping motor, rotates forward, the roller portion on the document tray 21 side moves up and down as indicated by a double arrow in FIG. 3. When the paper feed motor 107 rotates in the forward direction, as shown in FIG. 4, the paper feed mechanism 3 rotates clockwise, and the paper feed roller 4 rotates counterclockwise so that it is set on the document tray 21. The plurality of originals are separated from the upper original and fed one by one. Further, as shown in FIG. 5, the paper feed motor 107 is reversed, the paper feed mechanism 3 is stopped, and only the paper feed roller 4 rotates counterclockwise, thereby conveying the document.

  The pull-out sensor 14 detects a document sent from the document tray 21 by the paper feed mechanism 3, and the paper feed roller 4 detects the document sent by the paper feed mechanism 3 between the contact glass 19 and the transport unit 5. Feed paper.

  The registration sensor 15 is disposed in front of the contact glass 19 in the document conveyance direction by the paper feed roller 4, detects the document conveyed on the contact glass 19, and outputs it to the CPU 101 via the engine I / O 104. .

  The CPU 101 can detect the length of the document from the on / off timing of the pull-out sensor 14 and the registration sensor 15 and is used as a document standby position.

  As shown in FIG. 6, the conveyance unit (conveying means) 5 rotates the drive roller 5a counterclockwise and the conveyance belt 5b counterclockwise as the conveyance motor 108 rotates forward. The document transported between the transport belt 5b and the contact glass 19 by the paper feed roller 4 is transported to the document reading position on the contact glass 19 and temporarily stopped, and the document is read by the image reading unit of the image reading device. When reading of the image of the original is completed, the original of which the image has been read is conveyed to the paper discharge roller 6.

  Further, as shown in FIG. 7, when the conveyance motor 108 is reversed, the conveyance unit 5 rotates its driving roller 5a in the clockwise direction, and rotates the conveyance belt 5b in the clockwise direction to complete the reading once. After the reversed double-sided document is turned upside down by the switchback path 10, it is again conveyed back to the document reading position on the contact glass 19.

  The paper discharge entrance sensor (paper discharge entrance original detection means) 16 is disposed in front of the paper discharge roller 6 and detects the original conveyed to the paper discharge roller 6 by the transport unit 5 to detect the engine I / O. The data is output to the CPU 101 via O104.

  The switchback sensor 18 is provided in the switchback path 10 that is used when paper is discharged on one side of the document, and detects the presence or absence of a document in the switchback path 10.

  The paper discharge roller 6 conveys the original conveyed by the conveyance unit 5 to the double-sided claw 7, and the inclination of the double-sided claw 7 changes as the double-sided claw solenoid 111 is turned on / off as shown in FIG. Thus, switching is made between a paper discharge conveyance path for discharging the document through the paper discharge path 11 onto the paper discharge tray 20 at the paper discharge outlet roller 12 and a reverse conveyance path for conveying the original to the switchback path 10 via the switchback claw 8. To transport. The paper discharge roller 6, the double-sided claw 7, the switchback claw 8, and the paper discharge outlet roller 12 function as a paper discharge unit as a whole.

  As shown in FIG. 9, the inclination of the switchback claw 8 changes when the switchback claw solenoid 110 is turned on / off, and the document fed in the direction of the switchback claw 8 by the double-sided claw 7 is reversed again. A path of feeding in the direction of conveyance to the document reading position on the contact glass 19 by the conveyance unit 5 rotating in the opposite direction, and the document fed in the direction of the switchback claw 8 by the double-sided claw 7 are switched back by the switchback roller 9. The document is fed to the path 10 and switched from the switchback path 10 to the path for discharging the document on the switchback roller 9 through the sheet discharge path 11 onto the sheet discharge tray 20 through the sheet discharge outlet roller 12.

  The switch back roller 9 is rotationally driven by the paper discharge motor 109 and, as described above, performs normal rotation and reversal so that the document fed by the switch back claw 8 is fed into the switch back path 10. Then, the document in the switchback path 10 is sent out. The switchback claw 8, the switchback roller 9, and the switchback path 10 function as document reversing means as a whole.

  The paper discharge outlet roller 12 is rotationally driven by a paper discharge motor 109 and discharges the original conveyed to the paper discharge path 11 onto the paper discharge tray 20.

  A paper discharge clutch (clutch) 112 drives a paper discharge roller 6 that is driven and controlled by a paper discharge motor 109, among the paper discharge roller 6, the switch back roller 9, and the paper discharge outlet roller 12. Turn on / off. That is, when the paper discharge motor 109 rotates in the normal direction, the paper discharge roller 6, the switch back roller 9 and the paper discharge outlet roller 12 all rotate counterclockwise as shown in FIG. As shown in FIG. 11, the paper discharge roller 6 and the paper discharge outlet roller 12 rotate counterclockwise, and the switchback roller 9 rotates clockwise. If the paper discharge clutch 112 is off when the paper discharge motor 109 rotates forward or reverse, the paper discharge roller 6 becomes free as shown in FIG. Only the roller 12 rotates according to the normal rotation or reverse rotation of the paper discharge motor 109.

  Next, the operation of the present embodiment will be described. The automatic document feeder 1 according to the present embodiment, when performing the discharge operation and the reversing operation of two originals placed side by side on the contact glass 19 in succession, simultaneously with the completion of the discharge of the previous original, The second original is juxtaposed on the contact glass 19 after waiting for the original interval at which the front end of the original reaches the paper discharge sensor 16 at the time of reversal.

  As described above, the automatic document feeder 1 is assembled in an image reading apparatus as a main device such as a copying apparatus, and the image reading apparatus uses the automatic document feeder 1 to perform a copy operation of a plurality of documents. In this case, the user sets a plurality of documents on the document tray 21 of the automatic document feeder 1, and a single-side mode in which only one side of the document is read, a double-sided reading mode in which both sides of the document are read, and documents of different sizes are mixed. A necessary mode setting operation such as a mixed document mode is performed on the operation unit 201 of the image reading apparatus, and then the start key of the operation unit 201 is pressed.

  In the following description, it is assumed that two-sided reading is performed on two originals of A4 landscape size, hereinafter, the originals Org1 and Org2.

  In the automatic document feeder 1, when a plurality of documents are set on the document tray 21, the document setting sensor 13 detects the setting of the documents, and various setting operations are performed by the operation unit 201 of the image reading device. When the start key is pressed, as shown in FIG. 13, the first document Org1 is transported onto the contact glass 19 and the second document Org2 is advanced (group process GS1). .

  That is, in the group process GS1, the CPU 101 receives a paper feed / discharge command from the image reading apparatus (step S101), and starts feeding the first document Org1 by the paper feed mechanism 3 and the paper feed roller 4. Next, the CPU 101 sets the contact glass 19 on the surface Org1a of the first original document Org1 that has started feeding based on the number of rotations of the pullout sensor 14, the registration sensor 15, the paper feed motor 107, and the transport motor 108, and the like. The document is conveyed to the upper document reading position, stopped at the document reading position (step S102), a signal indicating the document stop is transmitted to the image reading apparatus, and the first document Org1 at the document reading position is transmitted by the image reading apparatus. When the reading of the front surface Org1a is started, at the same time, the calling motor 106 and the paper feed motor 107 are driven to carry out the first document feeding, in which the second document Org2 is conveyed to a predetermined document first feeding position and stopped (step). S103).

  Next, the first document Org1 is reversed and the back surface Org1b of the first document Org1 is set on the contact glass 19 (group processing GS2).

  That is, in the group processing GS2, when the CPU 101 completes reading of the surface Org1a of the first document Org1, it receives a reverse command from the image reading device (step S104), and the first sheet is conveyed by the transport unit 5 and the sheet discharge roller 6. The original Org1 is reversed (step S105). When the CPU 101 sets the back surface Org1b of the first document Org1 at the document reading position on the contact glass 19 (step S106), the CPU 101 transmits a document stop signal to the image reading device (step S107), and the image reading device reads the document. Reading of the original at the position is started.

  Next, the first document Org1 is discharged, and the front surface Org2a of the second document Org2 is set on the contact glass 19 (group processing GS3).

  That is, in the group processing GS3, when the CPU 101 completes reading of the back surface Org1b of the first original document Org1 and receives a paper supply / discharge command from the image reading apparatus (step S108), the CPU 101 first moves out the second original document Org2. After confirming completion (step S109), after discharging the first original document Org1 is started (step S110), it is confirmed that the discharge motor 109 has rotated N steps (step S111), and the paper is fed. The motor 107 is rotationally driven to start feeding the second original document Org2 (step S112). The reason why it is confirmed that the paper discharge motor 109 rotates by N steps is to set the optimal sheet interval (document interval) between the first document Org1 and the second document Org2. The number of N steps of the paper discharge motor 109 is set in advance. When the feeding of the second document Org2 is started, the CPU 101 confirms whether the front surface Org2a of the second document Org2 is set at the document reading position on the contact glass 19 (step S113).

  Next, the front side Org2a of the second document Org2 shown in FIG. 14 is read and reversed, and the back side Org2b is read (group processing GS4).

  That is, as shown in FIG. 14, the group processing GS4 is processing when the setting of the front surface Org2a of the second original document Org2 to the original reading position is not completed in step S113. Waiting for the entrance sensor 16 to be turned on (step S114), when the surface Org2a of the second document Org2 is set at the document reading position on the contact glass 19 (step S115), the first document Org1 is also Since the second document Org2 is also an A4 landscape document, the discharge operation of the first document Org1 is stopped and a document stop signal is transmitted to the image reading apparatus (step S116). When the image reading device receives the document stop signal, the image reading device starts reading the surface Org2a of the second document Org2 at the document reading position on the contact glass 19, and when the reading is completed, an inversion command is sent to the automatic document feeder 1. Send to.

  When the CPU 101 transmits a document stop signal to the image reading apparatus and then receives an inversion command from the image reading apparatus (step S117), the CPU 101 performs a paper discharge operation for the first document Org1, and the first document Org1. When the paper discharge is completed (step S118), the reversing operation of the second original document Org2 is started, and the switchback claw solenoid 110 is turned on (step S119).

  Then, when the back surface Org2b of the second document Org2 is set at the document reading position on the contact glass 19 (step S120), the CPU 101 transmits a document stop signal to the image reading device, and switches back claw solenoid 110. Is turned off (step S120).

  When the image reading device receives the document stop signal, the image reading device starts reading the back surface Org2b of the second document Org2 at the document reading position on the contact glass 19, and when the reading is completed, an inversion command is sent to the automatic document feeder 1. Send to.

  When the CPU 101 receives a paper discharge command from the image reading apparatus, the CPU 101 discharges the second original document Org2, and ends the process (step S123).

  When the document reading position setting of the front surface Org2a of the second document Org2 is completed in step S113 in FIG. 13, the CPU 101 arranges the two documents on the contact glass 19 as shown in FIG. The juxtaposition suitability determination process is performed (group process GS5).

  That is, in the group processing GS5, the CPU 101 first checks whether there are three documents on the contact glass 19 (step S124). If there are three documents, it is determined that a jam has occurred, and normal jam processing is performed. For example, each motor is stopped, a jam occurrence display is displayed on the display of the main body operation unit 201 of the image reading apparatus, and the process is terminated (step S125).

  If there are not three sheets on the contact glass 19 in step S124, the CPU 101 checks whether both the first document Org1 and the second document Org2 are smaller than the letter landscape size (step S126), and the document Org1. And the document Org2 are not smaller than the letter landscape size, it is checked whether or not the value obtained by adding the length between the papers Org1 and the document Org2 to the length of the paper (Org1 + Org2 + space) is equal to or greater than the specified value (step S127). .

  In step S127, if the value obtained by adding the length between the papers to the lengths of the document Org1 and the document Org2 is equal to or greater than the specified value, it is determined that a jam has occurred, and a normal jam process is performed to complete the process. If the value obtained by adding the length between the papers to the lengths of the originals Org1 and Org2 is not equal to or greater than the specified value, the paper discharge operation of the first original Org1 is stopped and the original stop signal is output. The image is transmitted to the image reading apparatus (step S128). When the image reading device receives the document stop signal, the image reading device starts reading the surface Org2a of the second document Org2 at the document reading position on the contact glass 19, and when the reading is completed, an inversion command is sent to the automatic document feeder 1. Send to.

  Next, the CPU 101 executes a discharge operation for the first original document Org1 and a reversal operation process for the second original document Org2 (group process GS6).

  That is, in the group process GS6, the CPU 101 first waits for reception of a reverse command from the image reading apparatus (step S129), starts the paper discharge operation of the first original Org1, and at the same time the second original. The reversing operation of Org2 is started, the discharge clutch 112 is turned on so that the discharge roller 6 follows the operation of the discharge motor 109, the double-side claw solenoid 111 is turned on, and the double-side claw 7 is pulled. Further, the switchback claw solenoid 110 is turned on, and the inclination of the switchback claw 8 is tilted toward the side of transporting the second original document Org2 to the switchback path 10, and the original document Org1 is discharged through the discharge path 11 to the discharge outlet roller. 12 secures a discharge conveyance path for discharging onto the discharge tray 20 and conveys the second original document Org2 to the switchback path 10. (Step S130). When the CPU 101 confirms that the trailing edge of the first document Org1 has passed through the paper discharge inlet sensor 16 (step S131), it turns off the double-sided claw solenoid 111 and returns the double-sided claw 7 to the normal state. Further, the paper discharge clutch 112 is turned off, the paper discharge roller 6 is returned to the free state, and the next original is prevented from entering the paper discharge path 11 (step S132).

  Then, when the trailing edge of the first original document Org1 passes the paper discharge outlet sensor 17 (step S133), the CPU 101 turns off the double-sided pawl solenoid 111 (step S134) and executes the group process GS7 shown in FIG. To do.

  In the group process GS7, when the trailing edge of the first original document Org1 passes through the paper discharge outlet roller 12, the rotational speed of the paper discharge motor 109 is decreased to prevent the originals from being scattered after being discharged.

  That is, in the group process GS7, as shown in FIG. 16, the CPU 101 passes the discharge motor 109 for M steps after the trailing edge of the first document Org1 passes the discharge outlet sensor 17 (step S135). Then, the rotational speed of the paper discharge motor 109 is lowered from 3400 pps to 2000 pps to reduce the paper discharge speed, and the discharged originals are prevented from being scattered on the paper discharge tray 20 (step S136).

  Next, the CPU 101 increases the speed of the paper discharge motor 109 so that the paper discharge roller 6 follows the paper discharge motor 109 in order to perform the reversing operation of the second original document Org2. GS9 processing is performed.

  That is, in the group processing GS8 and the group processing GS9, when the CPU 101 reduces the rotation speed of the paper discharge motor 109 from 3400 pps to 2000 pps, the CPU 101 waits for the paper discharge motor 109 to rotate by L steps (step S137). When the rotation speed of the paper motor 109 is increased from 2000 pps to 3400 pps (step S138), and the rotation speed of the paper discharge motor 109 is increased to 3400pps (step S139), the paper discharge clutch 112 is turned on and the paper discharge roller 6 is discharged. A state of following the motor 109 is set (step S140).

  Next, the CPU 101 sets the back surface Org2b of the second original document Org2 to the original reading position of the contact glass 19, and when the reading is performed, discharges the original document Org2 (group processing GS10).

  That is, in the group processing GS10, when the CPU 101 completes setting the back surface Org2b of the second document Org2 to the document reading position on the contact glass 19 (step S141), the CPU 101 transmits a document stop signal to the image reading device. The paper discharge clutch 112 is turned off and the switchback pawl solenoid 110 is turned off (step S142). That is, in the automatic document feeder 1, the document interval is set so that the subsequent document, in this case, the second document Org2 reaches the discharge roller 6 at the timing when the discharge clutch 112 is turned on. Therefore, when the second original document Org2 reaches the paper discharge inlet sensor 16, the paper discharge clutch 112 is turned on, and the reverse operation of the second original document Org2 is normally performed.

  When the image reading device receives the document stop signal, the image reading device starts reading the back surface Org2b of the second document Org2 at the document reading position on the contact glass 19. 1 to send.

  When the CPU 101 transmits a document stop signal to the image reading apparatus and then receives a paper discharge command from the image reading apparatus (step S143), the CPU 101 performs a paper discharge operation for the second original document Org2 (step S144).

  As described above, the automatic document feeder 1 according to the present embodiment separates a plurality of documents placed on the document tray 21 one by one by the paper feed mechanism 3 and reads the document on the contact glass 19. After the reading of the front surface of the document at the document reading position is completed, the front and back surfaces of the document are reversed by the double-sided claw 7, the switchback claw 8, the switchback roller 9 and the switchback path 10, and the back side is the document. The read document is transported to the reading position and transported by the discharge roller 6 and the discharge outlet roller 12 which are operated by the rotation operation of the discharge motor 109, and the read document is conveyed to the discharge or switchback path 10 to rotate the conveyance motor 108. The document on the contact glass 19 is conveyed to the sheet discharge roller 6 and the sheet discharge outlet roller 12 or conveyed to the document reading position by the conveyance unit 5 that operates by operation, and the sheet discharge roller sensor 16 contacts the contact glass 19 and the sheet discharge roller. The above-described units operate based on instructions from the main body control unit of the main body apparatus, and the double-sided read original and the front surface are placed on the contact glass 19 in the double-sided reading mode. When the two originals to be read are juxtaposed, the discharge operation of the double-sided read original and the reverse operation of the front-side original are continuously performed. The double-sided scanned document and the front-side scanned document are juxtaposed on the contact glass 19 at a document interval where the leading edge of the document is conveyed to a position detected by the paper discharge inlet sensor 16.

  Therefore, it is possible to prevent the occurrence of jamming and breakage of the document, and it is possible to eliminate a wasteful time from the completion of the discharge of the duplex scanned document to the start of the reversal of the front scanned document. And the processing speed at the time of double-sided reading can be improved.

  Further, the automatic document feeder 1 according to the present embodiment has a predetermined value in which the number of steps of the conveyance motor 108 is set in advance from the start of the conveyance operation in the paper discharge direction by the conveyance unit 5 of the double-sided document at the document reading position. At the point of time, the feeding of the next document on the document tray 21 by the paper feed mechanism 3 is started, thereby generating a document interval.

  Accordingly, it is possible to accurately control the document interval and reliably prevent the occurrence of jamming or breakage of the document, and a wasteful time from the completion of the discharge of the duplex scanned document to the start of the reverse of the front scanned document. Can be omitted more appropriately, the conveyance time of the double-sided original can be further shortened, and the processing speed at the time of double-sided reading can be further improved.

  Furthermore, the automatic document feeder 1 of the present embodiment has the same conveying speed by the conveying motor 108 to the discharge inlet sensor 16 of the front side scanned document as that of the front side scanned document at the time of the front / back reversing operation of the front side scanned document. Speed is up.

  Therefore, it is possible to more appropriately prevent the original from being jammed or damaged.

  Further, in the automatic document conveying device of the present embodiment, the paper discharge means is rotated by the paper discharge motor 109 and arranged along the document conveyance direction, and among the plurality of rollers, A paper discharge clutch 112 for turning on / off the connection of the paper discharge roller 6 in the uppermost stream in the document transport direction with the paper discharge motor 109. With the connection between the roller 6 and the paper discharge motor 109 turned off, the paper discharge motor 109 is rotated by a predetermined amount slower than the conveyance speed by the conveyance motor 108, and after the discharge of the discharged document is completed, the paper discharge When the rotation speed of the motor 109 is increased and the discharge speed of the discharge motor 109 reaches the transfer speed of the transfer motor 108, the discharge clutch 112 turns on the connection between the discharge roller 6 and the discharge motor 109. Te, and to perform the inversion operation by conveying the surface reading document reversing subject switchback path 10.

  Therefore, it is possible to more reliably prevent the occurrence of jamming or breakage of the document due to the difference in the document transport speed between the paper discharge motor 109 and the transport motor 108.

  The invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to the above, and various modifications can be made without departing from the scope of the invention. Needless to say.

  An automatic scanner that is mounted on image readers such as scanners, facsimile machines, and copiers, and that performs reverse reading of double-sided documents promptly without the waiting time for paper discharge completion and the waiting time for starting the paper discharge operation for reversed documents after paper discharge is completed. It can be applied to a document conveying device.

1 is a schematic front view of an automatic document feeder to which one embodiment of an automatic document feeder of the present invention is applied. FIG. 2 is a circuit block diagram of a main part of the automatic document feeder in FIG. 1. FIG. 4 is a diagram illustrating a sheet feeding operation of the sheet feeding mechanism in FIG. 1. FIG. 2 is an operation explanatory diagram of the sheet feeding mechanism and the sheet feeding roller in a state where the sheet feeding mechanism in FIG. 1 rotates clockwise and the sheet feeding roller rotates counterclockwise. FIG. 3 is an operation explanatory diagram of the sheet feeding mechanism and the sheet feeding roller in a state where the sheet feeding mechanism in FIG. 1 is stopped and only the sheet feeding roller is rotated counterclockwise. FIG. 3 is an operation explanatory diagram of the conveyance unit in a state where the conveyance unit of FIG. FIG. 2 is an operation explanatory diagram of the conveyance unit in a state where the conveyance unit of FIG. Operation | movement explanatory drawing of the double-sided nail | claw of FIG. Operation | movement explanatory drawing of the switchback nail | claw of FIG. FIG. 3 is an operation explanatory diagram of the paper discharge roller, the switch back roller, and the paper discharge outlet roller in FIG. 1. FIG. 3 is an operation explanatory diagram of the paper discharge roller, the switch back roller, and the paper discharge outlet roller in FIG. 1. FIG. 3 is an operation explanatory diagram of the paper discharge roller, the switch back roller, and the paper discharge outlet roller in FIG. 1. 2 is a flowchart showing a double-sided document conveyance control process by the automatic document conveyance device of FIG. 14 is a flowchart showing processing subsequent to the double-sided document conveyance control processing of FIG. FIG. 14 is a flowchart showing further subsequent processing of the double-sided document conveyance control processing of FIG. 13. FIG. FIG. 16 is a flowchart showing a further continuation process of the double-sided document conveyance control process of FIG. 15. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic document feeder 2 Case 3 Paper feed mechanism 4 Paper feed roller 5 Transport part 6 Paper discharge roller 7 Double-sided claw 8 Switchback claw 9 Switch back roller 10 Switchback path 11 Paper discharge path 12 Paper discharge exit roller 13 Document set Sensor 14 Pull-out sensor 15 Registration sensor 16 Paper discharge inlet sensor 17 Paper discharge outlet sensor 18 Switchback sensor 19 Contact glass 20 Paper discharge tray 21 Document tray 101 CPU
102 ROM
103 RAM
104 Engine I / O
105 Main unit I / F
106 Calling motor 107 Paper feed motor 108 Carrying motor 109 Paper discharge motor 110 Switchback claw solenoid 111 Double-side claw solenoid 112 Paper discharge clutch 113 Bus 201 Operation unit

Claims (4)

  The original reading on the contact glass is performed by separating a plurality of originals placed on the original table one by one, mounted on a main body apparatus that reads the image of the original stopped at the original reading position by moving the image reading means. A document feeding unit that transports the document to the position, a document reversing unit that reverses the front and back surfaces of the document and transports the back side to the document reading position after the reading of the front surface of the document at the document reading position is completed, and a discharge motor A paper discharge unit that operates by a rotation operation to discharge a read document or convey it to the document reversing unit; and a paper discharge unit that operates by a rotation operation of a conveyance motor to convey the document on the contact glass to the paper discharge unit or A conveying unit that conveys the document to a document reading position; and a sheet discharge entrance document detecting unit that detects the presence or absence of a document at a predetermined position between the contact glass and the sheet discharging unit. of Each of the above-mentioned means operates based on the indication, and is an automatic document feeder capable of juxtaposing two originals, a double-sided original and a front-side original, on the contact glass in the original double-side reading mode, In the double-sided reading mode, when the two-sided scanned document and the front-side scanned document are placed side by side on the contact glass, and the discharge operation of the double-sided scanned document and the reverse operation of the front-side scanned document are continuously performed, At the same time as the discharge of the double-sided scanned document is completed, the double-sided scanned document and the front-side scanned document are separated at a document interval in which the leading edge of the front-side scanned document is conveyed to a position detected by the discharge entrance document detection unit. An automatic document feeder which is juxtaposed on the contact glass.   The automatic document feeder includes a document conveyance distance measuring unit that measures a document movement amount on the contact glass based on the number of steps of the conveyance motor, and is provided by the conveyance unit of the double-sided scanned document at the document reading position. When the number of steps of the transport motor measured by the document transport distance measuring means reaches a predetermined value set in advance from the start of the transport operation in the paper discharge direction, the document feed means on the document table 2. The automatic document feeder according to claim 1, wherein the document interval is generated by starting feeding of the next document.   In the automatic document feeder, during the reversing operation of the front side scanned document, the transport speed of the front side scanned document to the discharge entrance document detection means by the transport motor is the same as the discharge speed by the discharge motor. 3. The automatic document feeder according to claim 1, wherein the speed is a speed. The automatic document feeder includes a plurality of rollers, the paper discharge means being rotated by the paper discharge motor and arranged along the document transport direction, and the most upstream roller in the document transport direction among the plurality of rollers. A clutch for turning on / off the connection of the paper discharge motor to the paper discharge motor, and the paper discharge means for discharging the discharged paper to connect the uppermost roller and the paper discharge motor. In a state where the paper discharge motor is turned off, the paper discharge motor is rotated by a predetermined amount slower than the conveyance speed by the conveyance motor, and after the discharge of the original to be discharged is completed, the rotation speed of the paper discharge motor is increased. When the discharge speed of the discharge motor reaches the transfer speed of the transfer motor, the clutch is turned on by the clutch to turn on the connection between the uppermost roller and the discharge motor, so Automatic document feeder according to claim 3, wherein the conveying the manuscript to the document reversing means to perform an inverting operation.

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