JP3573871B2 - Automatic document feeder - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an automatic document feeder mounted on an image reading device such as a facsimile machine, a copying machine, a scanner device, and more specifically, while automatically correcting the orientation of a document, automatically conveying and stopping the document on a contact glass. The present invention relates to an automatic document feeder that can be read on a contact glass.
[0002]
[Prior art]
2. Description of the Related Art Generally, in an automatic document feeder (hereinafter, also simply referred to as an ADF) used for an image reading device such as a facsimile machine, a copying machine, a scanner device, etc., an original placed on a document placing table is scanned with an image on a contact glass. After the document is automatically conveyed and stopped at the position, the document that has been read on the contact glass is discharged to a document discharge table provided at a predetermined position, whereby the document reading operation can be improved. Are known.
[0003]
By the way, if the document is simply conveyed and stopped on the contact glass, the document may be bent or misaligned, and the document may not be read at the regular reading position, resulting in deterioration of the reading performance. Therefore, the original can be read normally by abutting the original against the reference scale provided at the end of the contact glass, correcting the posture of the original such as bending or misalignment, and reading the original. So they can do it.
[0004]
That is, as shown in FIG. 18, the original 305 is brought into contact with a reference scale 304 provided at an end of the contact glass 303 by an endless transport belt 302 wound around a driving roller 301 and a driven roller (not shown). Then, the posture of the original 305 is corrected, and the original 305 is read in this state.
[0005]
[Problems to be solved by the invention]
However, in such a conventional automatic document feeder, the original 305 is brought into contact with the reference scale 304 in order to read the original 305 normally. However, as shown by a broken line in FIG. 18, the edge of the original 305 is bent and the edge of the original 305 rises from the contact glass 303 as shown by a broken line in FIG. As a result, a problem has arisen that the document 305 cannot be read normally.
[0006]
That is, as shown in FIG. 19, when the document is lifted by H from the contact glass 304, the light irradiated from the light source (not shown) onto the document during reading of the document is formed on the image forming surface 307a on the photosensitive drum 307 through the lens 306. When an image is formed, the image is expressed as a partial contraction phenomenon of the image due to the relationship of the angle of view of the lens 306.
More specifically, the contraction phenomenon means that a document b in which no floating occurs is read and an image is normally formed on the photosensitive drum 307 at a position B distant from the center of the lens 306. In the case where the document a raised from the position 303 by H is read and an image is formed on the photosensitive drum 307 at a position A away from the center of the lens 306, the distance from the center of the lens 306 to the end of the document The image is formed at a position shifted by an amount H raised from L, that is, when the image is formed on a straight line parallel to the sub-running direction of the document, which is expressed as a curved line or a contracted character. It is.
[0007]
When the original collides with the reference scale 304 in this way, a thin original cannot be read normally, and if the original does not abut against the reference scale 304 in order to normally read the original, the original Could not be corrected, and it was not preferable in any case.
SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic document feeder that can feed a document so that the image of the document can be read normally while correcting the position of the document.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention according to claim 1 is provided on a contact glass.Reading positionThe scanner is mounted on an image reading device that reads, Paper feed directionOriginals fed from the platenSaidTransfer onto contact glassTransport means for transporting the original in a paper discharge direction opposite to the paper feeding direction after completion of reading, a detection sensor for detecting a position of the original being transported,Conveyed on contact glassThe manuscriptButtingBeing saidCorrect the posture of the manuscriptAt the same time, the fed document is conveyed onto the contact glass based on the abutting member serving as a reference for the reading position and the position of the original detected by the detection sensor, and is abutted against the abutting member. Control means for controlling the conveying means so as to convey the original in the discharge direction after the reading is completed.Equipped with an automatic document feeder,The control means has a plurality of selectable modes including a thin paper mode for transporting a thin original and a thick paper mode for transporting a thick original, and the original is transported to a predetermined position near the reading position. Then, a slowdown that decelerates in accordance with the selected mode is performed, the document is stopped at a stop position that has passed a predetermined amount from the abutting member in the discharge direction, and the document has passed the predetermined amount and has stopped at the stop position. The stopped original is conveyed so as to return the excessive amount by a predetermined amount in the reverse paper feeding direction by performing a slow-up that accelerates according to the selected mode, and return the excessive amount by the predetermined amount. The document to be conveyed is subjected to the slowdown at a predetermined speed corresponding to the selected mode.The butting memberProtrudingPatchTo stop at the reading position and correct the orientation of the document, and when the thin paper mode is selected, the document stopped at the reading position isSeparated from butting memberSo that the paper ejectiondirectionPlaceTransfer only a fixed amount and waitControl the transport means as described aboveIt is characterized by:
[0009]
In that case,Went too farManuscriptput it backAfter the document is bent, the document is bent or misaligned, and the document is conveyed by a predetermined amount in a direction away from the butting member, thereby preventing the document from bending and floating from the contact glass. .At that time, the document that has gone too far is slowed down according to the selected mode and stopped, and when returning the document, the slow-up that accelerates according to the selected mode is performed. Since the slowdown is performed to hit the hitting member at a predetermined speed corresponding to the selected mode, the posture can be quickly corrected without damaging or disturbing the original.As a result, it is possible to prevent the occurrence of contraction phenomena such as bending of lines and contraction of characters when reading the document, and it is possible to read the document normally.
[0010]
According to a second aspect of the present invention, in order to solve the above-mentioned problem, in the first aspect of the present invention, the transport means has a transport member driven by a pulse motor.
In this case, the document can be reliably separated from the abutting member by a predetermined amount by the transporting member driven by the pulse motor, and the document can be accurately transported to a predetermined position separated from the abutting member.
[0011]
According to a third aspect of the present invention, in order to solve the above-mentioned problem, in the first or second aspect of the present invention, the abutting member is provided at an end of a contact glass, and when the end of the document abuts. And a reference scale constituting a reading reference position.
In such a case, for example, after a stopper member or the like is provided at a predetermined position on the conveyance path of the automatic document conveyance device to correct the posture of the document, and when the document is conveyed from the stopper member to the reading position, the conveyance time of the document is Becomes longer, and it is difficult to accurately position the reading position.
[0012]
When the document is separated from the reference scale constituting the reading reference position provided at the end of the contact glass as in the present invention, the document is separated from the reference scale by an amount corresponding to the bending of the document. Therefore, the document transport time can be shortened and the document can be accurately positioned at the reading position. Further, since the document need only be separated from the reference scale by an amount corresponding to the deflection of the document, it is possible to prevent the corrected document's posture from changing again, and to sufficiently correct the document's posture.
[0013]
According to a fourth aspect of the present invention, in order to solve the above-mentioned problem, in the first aspect of the present invention, a document is pressed against the abutting member immediately before an image of the document is read by the image reading device. After the contact, the transport unit is switched so as to perform one of a state in which the original is transported by a predetermined amount in a direction away from the abutting member and a state in which the original is abutted against the abutting member. It is characterized by having switching means for controlling.
[0014]
In such a case, a thick document such as a thick document that has high strength against buckling and does not bend even when struck against the striking member, is separated from the reference scale by a predetermined amount immediately before reading, and the document is moved by the moving amount. Posture may change. For this reason, by controlling the transport state of the transport means as described above, in the case of a thick original, the original is changed while being read while being abutted against the abutting member. In the case of a thin original, reading is performed with a predetermined amount of separation from the abutting member, so that the original is flexed and rises from the contact glass. Can be prevented.
According to a fifth aspect of the present invention, there is provided an image reading apparatus for reading an image of a document stopped at a reading position on a contact glass, wherein the document is fed from a document table in a feeding direction. Transport means for transporting the original document onto the contact glass, and after the reading is completed, transporting the original document in a sheet discharging direction opposite to the paper feeding direction, and detecting a position of the original document being transported. A detection sensor, the original conveyed on the contact glass is abutted to correct the orientation of the original, and an abutting member serving as a reference for the reading position; Based on the position, the fed document is conveyed onto the contact glass, abutted against the abutting member and stopped at the reading position, and after the reading is completed, the document is ejected. The control method of the automatic document feeder provided with control means for controlling the conveyance means to convey in the direction, the control means, a thin paper mode for conveying a thin document, and a thick paper mode for conveying a thick document When the document is conveyed to a predetermined position near the reading position, the document is conveyed to a predetermined position near the reading position. Stopping the document at a stop position that has passed a predetermined amount from the abutting member in the sheet discharging direction, and performing a slow-up that accelerates the document stopped at the stop position after the predetermined amount has passed. Transporting the over-traveled predetermined amount in the reverse paper feed direction; and And stopping at the reading position by abutting against the abutting member at a predetermined speed corresponding to the selected mode, and correcting the orientation of the original, and when selecting the thin paper mode, Transporting the original stopped at the reading position by a predetermined amount in the paper discharge direction so as to be separated from the abutting member, and making the original stand by, thereby controlling the transporting means.
In such a case, the original that has gone too far to the abutting member is returned and abutted to correct the bending or misalignment of the original, and then the original is conveyed by a predetermined amount in a direction away from the abutting member. It can be prevented from bending and floating from the contact glass. At that time, the document that has gone too far is slowed down according to the selected mode and stopped, and when returning the document, the slow-up that accelerates according to the selected mode is performed. Since the slowdown is performed to hit the hitting member at a predetermined speed corresponding to the selected mode, the posture can be quickly corrected without damaging or disturbing the original. As a result, it is possible to prevent the occurrence of contraction phenomena such as bending of lines and contraction of characters when reading the document, and it is possible to read the document normally.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 17 are diagrams showing an embodiment of the automatic document feeder according to the present invention. The present invention is applicable to a copier, a facsimile apparatus, a scanner apparatus, and the like having a reading mechanism for reading a document stopped on a contact glass.
[0016]
First, the configuration will be described. 1 and 2, reference numeral 1 denotes an automatic document feeder (hereinafter, referred to as an ADF), and the ADF 1 is provided above a copying machine that forms an image reading device (not shown) and forms a part of an exposure position. Is covered.
The ADF 1 includes a document table 3 on which a document bundle including a plurality of documents can be placed, and a lowermost document separated from the document stack on the document table 3 one by one and fed. Separating / transporting means 4 for transporting toward the glass 2, transporting means 5 for transporting the document separated / transported from the separating / transporting means 4 to a reading / exposing position on the contact glass 2, Paper discharge means 7 having a paper discharge path for discharging the read document onto the document discharge section 6 and a turn path for reversing the document during double-sided document copying and returning it to the contact glass 2 again; .
[0017]
The separating / transporting means 4 includes a document stopper 8 which, when a document bundle is set on the document placing table 3, comes into contact with the leading end of the document bundle to prevent the document bundle from entering inwardly; A document set detection filler 9 that moves upward by contacting the leading end of the document bundle set on the document 3; a document set sensor 10 that detects the detection filler 9 in proximity to and separated from the detection filler 9; A press lever 12 that is close to the call roller 11 when the sensor 10 detects separation from the set sensor 10, presses a bundle of documents against the call roller 11, and feeds the document bundle together with the call roller 11. I have.
[0018]
The document stopper 8 is fixed to a recall drive shaft 13 as shown in FIGS. 3 and 4, and a press lever 12 is fixed to the drive shaft 13 via a recall arm 14. And are connected rotatably. A document stopper 8 is connected to the drive shaft 13 so as to be swingable relative to the drive shaft 13. The stopper 8 is restricted from moving in the thrust direction by an E-ring (not shown). Notches 8a and 9a are formed in the document stopper 8 and the filler 9, respectively, and the notches 8a and 9a are in contact with each other to restrict the rotation of the filler 9 more than one rotation.
[0019]
The drive shaft 13 is connected to a call solenoid 17 as shown in FIG. 2, and the solenoid 17 is driven by a main control unit 18. The main control unit 18 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like, and executes a basic operation of the ADF 1.
[0020]
The calling solenoid 17 always rotates the rotary shaft 13 to a predetermined position by the lever 17a being urged by the spring 17b. In this state, the original stopper 8 prevents the original bundle from entering and the pressing lever Reference numeral 12 is separated from the call roller 11 (see FIG. 5). That is, the calling solenoid 17 is formed of a keep solenoid, and the plunger once pulled is kept as it is by the magnetic force of the keep solenoid.
[0021]
The calling solenoid 17 detects that the document set sensor 10 has set the document bundle, outputs a signal from the set sensor 10 to the main control unit 18, and when the start switch is pressed, the main control unit By turning ON based on the signal from the signal 18, the turning shaft 13 is turned in a direction opposite to a predetermined direction against the urging force of the spring 17b, and the document stopper 8 is separated from the leading end of the document bundle. The presser lever 12 is brought into contact with the retrieving roller 11 via a document bundle (see FIG. 6).
[0022]
A compression spring 16 is interposed between the presser lever 12 and the retrieving arm 14. The compression spring 16 has a sufficient pressing force when the presser lever 12 comes into contact with the retrieving roller 11 via the document bundle. To press the document bundle.
A separation roller 19, a separation belt 20, a pull-out driving roller 21, and a pull-out driven roller 21 a that is brought into contact with a pull-out driving roller 21 by a spring (not shown) are disposed downstream of the retrieving roller 11 in the document conveying direction. ing. The separation belt 20 is composed of an endless belt, and is driven by a separation belt driving roller 22. Then, the bundle of originals fed by the recall roller 11 is temporarily stopped between the separation roller 19 and the separation belt 20, and then the lowermost original is separated by the frictional force between the separation roller 19 and the separation belt 20. Thereafter, the sheet is conveyed toward the contact glass 2 by the separation roller 19 and the pull-out drive roller 21.
[0023]
When the registration sensor 100 detects the leading end of the bundle of documents conveyed toward the contact glass 2, the driving of the calling roller 11 and the separation roller 19 is stopped, and the separation belt 20 and the pull-out driving roller 21 move the document. It is conveyed toward the contact glass 2.
The above-described call roller 11, separation roller 19, separation belt 20, and pull-out driving roller 21 are driven via a transmission mechanism 24 by a sheet feeding motor 23 which is a stepping motor of the present invention.
[0024]
That is, the driving force of the feed motor 23 is transmitted to the driven pulley 26 via the timing belt 25, and the driven pulley 26 transmits the driving force to the pulley 28 via the connecting shaft 27. Has become. The pulley 28 transmits a driving force to a pulley 30 via a timing belt 29, and the pulley 30 transmits a driving force to gears 32 and 33 via a rotating shaft 31. The gear 32 is connected to the separation belt driving roller 22 via a gear group 34 and a rotating shaft 35, and the gear 32 is rotatable only in a counterclockwise direction by a one-way clutch. The gear 32 is connected to a gear 37 rotatable only in the counterclockwise direction by a one-way clutch via an idler gear 36. The gear 37 is connected to a gear 39 rotatable only in the counterclockwise direction by the one-way clutch by a rotating shaft 38. It is connected to the pull-out drive roller 21.
[0025]
On the other hand, the gear 33 is rotatable only in a clockwise direction by a one-way clutch, and is meshed with the gear 40. The gear 40 is connected to the separation roller 19 via a rotating shaft 41. The gear 33 also meshes with a gear 39. The gear 39 meshes with a gear 43 rotatable only in a counterclockwise direction by an one-way clutch via an idler gear 42, and the gear 43 is recalled via a rotary shaft 44. It is connected to the roller 11.
[0026]
Therefore, when the paper feed motor 23 is rotated clockwise in FIG. 2, the paging roller 11, the separation roller 19, and the pull-out driving roller 21 rotate counterclockwise with the separation belt 22 stopped, and When the sheet separation is performed and the leading end of the separated document is detected by the registration sensor 100, the sheet feeding motor 23 is stopped by a command from the main control unit 18 and then the sheet feeding motor 23 By rotating in the clockwise direction, the rotation of the calling roller 11 and the separation roller 19 is stopped, and the separation belt 20 and the pull-out drive roller 21 rotate to prevent the subsequent document from being separated and contact the separated document. It is conveyed toward the glass 2.
[0027]
The paper feed motor 23 is formed of a four-phase stepping motor. The torque and the rotation speed of the paper feed motor 23 are controlled by a motor driver (not shown), and the motor driver is controlled by the main control unit 18. ing.
The motor driver varies the pulse width of the signal supplied to each coil of the paper feeding motor based on the four-phase input signal input from the main control unit 18 to vary the rotation speed of the paper feeding motor 23. ing.
[0028]
The registration sensor 100 detects the front and rear ends of the document and outputs a signal to the main control unit 18. Reference numeral 102 denotes a document width detecting sensor serving as a document width detecting unit. The sensor 102 detects the length of the document in the width direction and outputs document size information to the main control unit 18.
Specifically, the sensor 102 includes three sensors separated in the width direction of the document, and detects the size of the document according to each detection position as is well known.
[0029]
A pulse generator (not shown) is provided on the rotation shaft of the pull-out driven roller 21a, and a pulse generated by the pulse generator is detected by the document length detection sensor 103. The detection signal from the sensor 103 is output to the main control unit 18.
When the detection information of the front and rear ends of the document is input by the registration sensor 100, the main controller 18 counts the pulse signals when passing the front and rear ends, and also determines the document length by the feed amount of the document per pulse. Calculation and determination.
[0030]
When the detection information of the front and rear ends of the original is input by the registration sensor 100, the main controller 18 counts the pulse signal of the motor driver that drives the paper feed motor 23 when passing through the front and rear ends, and also outputs one pulse per pulse. The length of the original is calculated and determined according to the amount of the original fed.
Then, the main controller 18 finally detects the document length based on the pulse signal from the sensor 103 and the pulse signal from the paper feed motor 23. Further, the main control section 18 displays the fact on a display section provided in the copying machine main body when the detection of the document length is abnormal. In the present embodiment, the paper feed motor 23 constitutes first rotation amount detection means for detecting the rotation amount of the rotation shaft of the driving roller 21, and the pulse generator and the document length detection sensor 103 serve as the rotation shaft of the driven roller 21 a. The second rotation amount detection means for detecting the rotation amount is constituted, the registration sensor 100 constitutes the document detection means, and the main control section 18 constitutes the document length detection means. Instead of counting the number of pulses of the paper feed motor 23 and detecting the rotation amount of the pull-out driving roller 21, the rotation amount of the rotation shaft of the pull-out driving roller 21 may be detected by a pulse generator and a sensor.
[0031]
On the other hand, the transporting means 5 is composed of a transport belt unit 200 as shown in FIG. 7, and the transport belt unit 200 is rotatably attached to the main frame 201 mounted on the ADF 1 main body and the main frame 201. And a channel 202.
The transport belt unit 200 is separated from the contact glass 2 in the document transport direction and is rotatably provided on the main frame 201 and the channel 202. The drive roller 51 and the driven roller 52 are wound around the rollers 51 and 52. And an endless transfer belt 53 made of rubber, which is provided across the main frame 201 and the channel 202 and has a smooth back surface. The transfer belt 53 and the contact glass 2 are provided rotatably on the main frame 201. The main body 201 and the channel 202 are provided on the main frame 201 and the channel 202 so as to be separated from each other by a predetermined distance in the extending direction of the contact glass 2. A plurality of rows of pressing rollers 55 to be pressed It is configured. In this embodiment, the drive roller 51 and the transport belt 53, which are components of the transport unit 5, constitute a transport member.
[0032]
The transport unit 5 transports a document to a reading / exposing position by the transport belt 53 and transports the exposed document from the contact glass 2 to the paper discharge unit 7.
The drive roller 51 is connected to a transport belt motor 58 composed of a pulse motor via a transmission mechanism 57, and is driven by the transport belt motor 58. The transport belt motor 58 is connected to a driven pulley 60 via a timing belt 59, and the driven pulley 60 transmits the driving force of the transport belt motor 58 to a pulley 62 via a timing belt 61. The pulley 62 is connected to the driving roller 51 via a rotating shaft 63, and transmits the driving force from the conveyor belt motor 58 by the above-described members.
[0033]
The conveyance belt motor 58 is driven by the main control unit 18 in the counterclockwise rotation direction in FIG. 2 to convey the document together with the separation belt 20 and the pull-out driving roller 21 toward the reading / exposing position of the contact glass 2. When a signal indicating that the trailing end of the separated document is detected from the registration sensor 100 is input to the main control unit 18, the main control unit 18 stops driving the sheet feeding motor 23, and then sets a predetermined number of pulses. Driven.
[0034]
The setting pulse is set to be different between the thick paper mode for reading a thick original and the thin paper mode for reading a thin original.
That is, in the case of the thin paper mode, after the document is once overrun from the reference scale (abutting member) 56, the drive roller 51 is rotated clockwise in FIG. 1 to move the transport belt 53 clockwise. By switching back the original, the rear end of the original abuts against the reference scale 56 to correct the posture of the original such as bending or misalignment, and then the driving roller 51 is rotated counterclockwise in FIG. By moving the transport belt 53 in the counterclockwise direction, the document is stopped at a predetermined distance a (a = about 0.5 to 1.0 mm) as shown in FIG. Set to the number of pulses.
[0035]
In the case of the thick paper mode, after the registration sensor 100 detects the rear end of the document, the driving roller 51 is rotated clockwise in FIG. 1 to move the transport belt 53 clockwise to switch the document. The counter is counted only for the distance in which the back end of the document is brought into contact with the reference scale 56 by being backed.
Then, the document is read and exposed at this reading / exposure position by a known reading device including a light source, a mirror, and a lens provided below the contact glass 2 and a known exposure device including a photosensitive drum.
[0036]
The setting of the thick paper mode and the thin paper mode is performed by operating a mode setting switch (not shown) provided at a predetermined portion of the ADF 1 or the operation unit of the copier main body. This is performed by operating the belt motor 58. That is, in the present embodiment, the mode setting switch and the main control unit 18 constitute a switching unit.
[0037]
On the other hand, in the present embodiment, since the channel 202 is rotatably attached to the main frame 201, by rotating the channel 202 counterclockwise in FIG. 53 can be easily detached.
The paper discharging means 7 is provided with a reversing guide 71 which extends upward from the driven roller 52 side of the contact glass 2 in a curved manner, and a reversing drive provided along the guide 71 and operated by a reversing / paper discharging motor 72. A roller 73 and a sheet discharge driving roller 75, a guide roller 74 provided downstream of the reversing driving roller 73 and rotatably supported by the ADF 1 main body 1 a, and a reversing driving roller provided downstream of the guide roller 74. After the original conveyed by 73 is discharged by the discharge driving roller 75 to the document discharge section 6 as it is and the upper and lower surfaces of the document are reversed, the document is reversed by the reverse driving roller 73 and the reverse exit driven roller 76. And a switching claw 78 which can be switched to a second switching position for returning to the contact glass 2 through the turn passage 77 while being pinched by the switch (see FIG. 8).
[0038]
The reversing / discharge motor 72 is driven by the main control unit 18 and is connected to a driven pulley 80 via a timing belt 79. The driven pulley 80 is connected to a pulley 82 via a rotation shaft 81, and the pulley 82 transmits a driving force from a motor 72 to pulleys 84 and 85 via a timing belt 83. The pulley 84 is connected to a paper discharge roller 75 via a rotation shaft 86, and the pulley 85 is connected to a reversing drive roller 73 via a rotation shaft 87. The discharge roller 75 and the reversal drive roller 73 The driving force from the reversing / discharge motor 72 is transmitted via each member.
[0039]
On the other hand, the switching claw 78 is connected to a reversing solenoid 89 via a driving shaft 88, and the reversing solenoid 89 is turned ON / OFF by the main control unit 18. When the reversing solenoid 89 is turned off, the switching shaft 78 is switched to the first switching position by pulling the drive shaft 88 in the direction of arrow B by the return spring 90. Is discharged to The reversing solenoid 89 is turned on based on the output signal from the main control unit 18 in the double-sided mode. At this time, the drive shaft 88 is pulled in the direction of arrow A against the pulling force of the return spring 90. As a result, the switching pawl 78 is switched to the second switching position, and the original is returned to the contact glass 2.
[0040]
A paper discharge sensor 104 is provided between the reversing drive roller 73 and the guide roller 74, and the paper discharge sensor 104 detects a document and outputs the detection information to the main control unit 18. The main control unit 18 drives the reversing solenoid 89 based on the detection information to change the document discharge position.
Next, a method of transporting a document by the ADF 1 will be described with reference to flowcharts shown in FIGS. This flowchart shows a program stored in the ROM of the main control unit 18 and executed by the CPU.
[0041]
First, the original bundle is placed on the original placing table 3 so that the image side of the original faces upward, and is set at a position where the leading end of the original abuts against the original stopper 8 at the entrance of the paper feeding unit. The document bundle set to the position where it abuts the document stopper 8 lifts the detection filler 9 and determines whether or not the document set sensor 10 has detected that the document bundle has been set on the document table 3 ( In step S1), when the document set sensor 10 is turned ON, it is determined whether or not a mode signal (whether the mode is the duplex mode or the simplex mode) is input (step S2).
[0042]
Next, it is determined whether or not the mode signal is a one-sided mode signal (step S3). If it is determined that the mode signal is a one-sided mode signal, it is determined whether or not the start switch is pressed in the state set in the mode. That is, it is determined whether or not a paper feed signal has been input (step S4). On the other hand, if the signal is not the one-sided mode signal, it is determined that the mode is the two-sided mode, and it is determined whether or not the start switch is pressed in the state where the mode is set, that is, whether or not the sheet reversal signal is input. (Step S5).
[0043]
When either the paper feed signal or the paper feed reversal signal is input in step S4 or step S5, the calling solenoid 17 is turned on, the paper feed motor 23 is driven forward in the clockwise direction, and the transport belt motor 58 is driven. The counterclockwise rotation is driven forward and the reversing / discharge motor 72 is driven counterclockwise to rotate forward. At this time, the motors 23, 58, and 72 are started up slowly, and the number of pulses of each motor is counted (step S6).
[0044]
That is, when the calling solenoid 17 is turned on, the rotating shaft 13 is rotated against the urging force of the spring 17b, the original stopper 8 moves upward from the original bundle S, and the pressing lever 12 is moved through the original bundle S via the original bundle S. Since the document bundle comes into contact with the call roller 11 (see FIG. 6), the document bundle is fed by the call roller 11 and conveyed between the separation roller 19 and the separation belt 20. At this time, since the separation belt 20 is stopped because the gear 32 is prevented from rotating counterclockwise by the one-way clutch, the separation belt 20 is moved to the lowermost position of the original bundle by frictional separation by the separation roller 19 and the separation belt 20. The located document is separated, and only this document is conveyed by the separation roller 19, the pull-out driving roller 20, and the pull-out driven roller 20a. At this time, the main controller 18 inputs a four-phase signal to the motor driver with a gradually shortened pulse width, thereby gradually shortening the pulse width when the coil is excited by the motor driver to feed the paper. The motor 23 is started by slow-up.
[0045]
Then, it is determined whether or not the slow-up of each of the motors 23 and 58 has been completed since the separation of the document was started (step S7). When it is determined that the slow-up has been completed, based on the detection information from the registration sensor 100, it is determined. It is determined whether the leading edge of the document has been detected (step S8).
If the registration sensor 100 is not ON, it is determined whether or not the pulse count of the paper feed motor 23 has reached the set value A (step S9). The set value A is the number of pulses obtained by adding the jam detection allowance distance to the distance from the leading end of the document set on the document table 3 to the registration sensor 100. Therefore, if it is determined in step S9 that the registration sensor 100 has not been turned on and the number of pulses of the paper feed motor 23 has reached the pulse count A, it is determined that a jam has occurred and the processing shown in FIG. Execute.
[0046]
That is, as shown in FIG. 14, after each motor 23, 58, 72 is slowed down (step S71), it is determined whether each motor 23, 58, 72 has completed the slowdown (step S72). When it is determined that the slowdown of each of the motors 23, 58 and 72 has been completed, all the motors 23, 58 and 72 are stopped (step S73). Usually, in this state, the user performs the work of removing the jammed paper from the ADF 1. Therefore, it is determined whether or not the jammed paper is released based on the detection information from the registration sensor 100 and the width detection sensor 102, and the jammed paper is released. If it is determined that the process has been completed, the process of FIG. 10 is executed again from the start.
[0047]
On the other hand, if it is determined in step S8 that the registration sensor 100 has been turned ON, the paper feed motor 23 and the transport belt motor 58 are started at a slow speed (step S10). In order to start the paper feed motor 23 in a slow down manner, the main controller 18 inputs a four-phase signal with a gradually increasing pulse width to the motor driver, so that the pulse when the coil is excited by the motor driver is input. By gradually increasing the width, the feed motor 23 is started at a slowdown.
[0048]
Next, it is determined whether or not the slowdown start of the sheet feeding motor 23 and the conveyance belt motor 58 has been completed (step S11). In step S12), the process proceeds to the flow of FIG. 11, and the sheet feeding motor 23 is driven to rotate in the counterclockwise direction and the conveyor belt motor 58 is driven to rotate in the counterclockwise direction. The number is counted (step S13).
[0049]
At this time, the rotation of the gear 33 by the one-way clutch is restricted by the reverse rotation drive of the paper feed motor 23, the calling roller 11 and the separation roller 19 are stopped, and only the pull-out driving roller 21 rotates counterclockwise.
Further, the one-way clutch in the gear 32 is disengaged and the separation belt driving roller 22 is rotated, and the separation belt 19 stopped at the time of separation rotates clockwise, that is, in the direction opposite to the document conveyance. 11. By stopping the separation roller 19 and rotating the separation belt 20, the next document is prevented from entering the separation nip portion, and the previously separated and conveyed document is pulled out by the pull-out drive roller 21, the driven roller 21a, and the conveyance motor 58. The conveyance belt 53 is conveyed from the separation / conveyance means 4 to the conveyance means 5 by the counterclockwise rotation of the conveyance belt 53 by the drive.
[0050]
Next, it is determined whether or not the slow-up of the motors 23 and 58 has been completed (step S14). When the slow-up has been completed, whether or not the sensor 100 has been turned off based on the detection information from the registration sensor 100, that is, the separation It is determined whether or not the trailing edge of the document has been detected (step S15). If the registration sensor has not been turned off, it is determined whether or not the number of pulses of the paper feed motor 23 has reached the set value C (step S15). Step S16). The set value C is set to a length obtained by adding a jam detection allowance distance to the maximum original length in the feeding direction.
[0051]
If the number of pulses of the paper feed motor 23 has reached the set value C with the registration sensor turned off in step S16, the jam processing shown in FIG. 14 is executed. If it is determined in step S15 that the registration sensor 100 has been turned off, the sheet feeding motor 23 is turned off to stop the separation belt 19 and the pull-out driving roller 21, and only the transport belt motor 58 is driven to drive the document. Is transported onto the contact glass 2 (step S17).
[0052]
Subsequently, the flow shifts to the flow shown in FIG. 12, and it is determined whether or not the mode is the one-sided butting mode (step S18). It is determined whether or not the pulse count value of 58 has reached the pulse set value H (step S19).
The set value H is set to a value obtained by adding about 7 mm to the above-described pulse set value B. When the pulse set value H is reached, the sheet feed motor 23 and the transport belt motor 58 are slowed down and started ( Step S20), it is determined whether or not the slowdown of the motors 23 and 58 has been completed (step S21).
[0053]
If it is determined that the slowdown of the sheet feeding motor 23 and the conveying belt motor 58 has been completed, the driving of the sheet feeding motor 23 and the conveying belt motor 58 is stopped (step S22). For this reason, the document is stopped on the contact glass 2 with the rear end portion slightly separated from the reference scale 56 toward the sheet discharging means 7.
Next, the transport belt 53 is moved in the clockwise direction by driving the transport belt motor 58 in the clockwise direction in a slow-up direction, thereby counting the number of pulses of the transport belt motor 58 (step S23).
[0054]
Next, it is determined whether or not the slow-up of the motor 58 has been completed (step S24). When it is determined that the slow-up has been completed, whether or not the pulse count value of the conveyor belt motor 58 has reached the pulse set value I is determined. Is determined (step S25). The pulse set value I is set to a value obtained by subtracting the distance required for slowing down the conveyor belt motor 58 from about 12 mm. When it is determined that the pulse count value of the motor 58 has reached the pulse set value I, After the slowdown of the conveyor belt motor 58 is started (step S26), it is determined whether or not the slowdown of the motor 58 is completed (step S27).
[0055]
Next, when it is determined that the slowdown has ended, the driving of the conveyor belt motor 58 is stopped. Next, it is determined whether or not the thin paper mode has been set by the mode setting switch (step S29). If the thin paper mode has been set, the transport belt motor 58 is driven forward in the counterclockwise direction, and the transport belt motor 58 is driven. The number of pulses of 58 is counted (step S30). Next, it is determined whether or not the number of pulses has reached the set value K (step S31). This set value K is set to the number of pulses corresponding to the distance separated from the reference scale 56 by about 0.5 to 1.0 mm as shown in FIG.
[0056]
When it is determined that the number of pulses of the conveyor belt motor 58 has reached the set value K, the driving of the conveyor belt motor 58 is stopped (step S32). As a result, the document conveyed onto the contact glass 2 is once overrun from the reference scale 56 on the contact glass 2, and is then switched back so that the rear end abuts against the reference scale 56 to correct the posture. After that, by being separated from the reference scale 58 by a distance corresponding to the set value K, the bending is removed and the contact glass 2 is positioned at the reading / exposing position.
On the other hand, if the thin paper mode is not set in step S29, it is determined that the thick paper mode has been set by the mode setting switch, and the conveyance belt motor 58 is kept stopped. As a result, the document conveyed onto the contact glass 2 is once overrun from the reference scale 56 on the contact glass 2, and is then switched back so that the rear end of the original is abutted against the reference scale 56 to read the document on the contact glass 2.・ It is positioned at the exposure position.
[0057]
Both thick paper and thin paper originals are read and exposed at this reading / exposure position by reading means including a light source, a mirror, and a lens, and exposing means including a photosensitive drum.
Next, the transport belt motor 58 is driven to rotate forward in the counterclockwise direction, and the process proceeds to step S33 to determine whether or not the leading end of the document has reached the paper discharge sensor 104. If it is determined that the leading end of the document has not reached the paper discharge sensor 104, it is determined whether the pulse count value of the transport belt motor 58 has reached the pulse set value D (step S34). Here, the pulse set value D is set to a value obtained by adding a jam detection allowance distance to the distance from the leading edge of the document on the contact glass 2 to the paper ejection sensor 104.
[0058]
If it is determined in step S34 that the pulse count value of the motor 58 has reached the pulse set value D even though the leading edge of the document has not reached the paper ejection sensor 104, the jam processing shown in FIG. 14 is executed. If the pulse count value of the motor 58 has not reached the pulse set value D, the reversing / discharge motor 72 is slow-down started (step S35), and when it is determined that the slow-down has ended (step S35). (YES in S36), the inversion / discharge motor 72 is stopped (step S37).
[0059]
For this reason, the leading end of the document carried out of the contact glass 2 is conveyed to the paper discharging means 7 and reaches the reversing drive roller 73. Next, as shown in FIG. 13, it is determined whether or not there is a next document (step S38). If there is no next document, it is determined whether or not the discharge of the last document has been completed (step S39). . If it is determined that the discharge of the last document has been completed, the process returns to the start position of the processing shown in FIG. 10, and if it is determined that the discharge of the last document has not been completed, the calling solenoid 17 is turned off. Then, the document stopper 8 is moved downward, and the presser lever 12 is separated from the calling roller 11 (step S40).
[0060]
Next, when a paper discharge signal is input (step S41), the transport belt motor 58 is driven counterclockwise, the reversing / paper discharge motor 72 is driven forward in the counterclockwise direction with slow-up, and both motors 58, 72 are rotated. Are counted (step S42). For this reason, the original is carried out of the contact glass 2 by the transport belt 53 and the reverse driving roller 73.
[0061]
Next, it is determined whether or not the slow-up of the motors 58 and 72 has been completed (step S43), and if it is determined that the slow-up start has been completed, it is determined whether or not the sheet discharge sensor 104 has been turned on (step S44). ). At this time, when the paper discharge sensor 104 detects the leading end of the document and the sensor 101 is turned on, the processing shown in FIG. 15 is executed.
[0062]
First, it is determined whether or not the transport belt motor 58 is ON (step S45). If the transport belt motor 58 is ON, the transport belt motor 58 is started down slowly (step S46). It is determined whether or not the slowdown of the conveyor belt motor 58 has been completed (step S47).
Here, when the slowdown is completed, the transport belt motor 58 is stopped (step S48). After the conveyance belt motor 58 stops, or in a state where the conveyance belt motor 58 is not turned on in step S45, it is determined whether or not the pulse count value of the reversing / discharge motor 72 has reached the pulse set value E ( Step S49). This set value E is set to a distance shortly before the trailing edge of the document passes through the paper discharge sensor 104. When the set value E is reached, the reverse / paper discharge motor 72 is slowed down (decelerated). After that (Step S50), it is determined whether or not the slowdown of the reversing / discharge motor 72 has been completed (Step S51). When it is determined that the slowdown has been completed, the discharge sensor 104 is turned off. It is determined whether or not it is (step S52).
[0063]
If the discharge sensor 104 has not been turned off, it is determined whether or not the pulse count value of the reversing / discharge motor 72 has reached the pulse set value G (step S53). The pulse set value G is set to a value obtained by adding a jam detection allowance distance to the length of the document being discharged in the feeding direction. When the pulse count value of the reversing / discharge motor 72 has reached the set value G, the jam processing shown in FIG. 14 is executed, and when the pulse count value has not reached the pulse set value G, the flow proceeds to step S52. Return.
[0064]
On the other hand, if the paper discharge sensor 104 is turned off in step S52, it is determined that the trailing end of the document has been detected by the paper discharge sensor 104, and the pulse count value of the reversing / paper discharge motor 72 has reached the set value F. It is determined whether or not this is the case (step S54). The set value F is set to a value obtained by adding a predetermined margin distance to the distance from the sheet discharge sensor 104 to the sheet discharge drive roller 75. When it is determined that the set value has been reached, the reverse / sheet discharge motor 72 is set. Is started (step S55), it is determined whether or not the slowdown of the reversing / discharge motor 72 is completed (step S56).
[0065]
If it is determined that the slowdown of the reversing / discharge motor 72 has ended, the reversing / discharge motor 72 is stopped (step S57). That is, in the processing from step S45 to S57, the reversing / discharge motor 73 is driven to drive the reversing drive roller 73 and the discharge drive roller 75, so that the reversal drive roller 73, the discharge drive roller 75 and the guide are driven. In this process, the original is guided along the reversing guide 71 by the rollers 74, and the original is discharged to the original discharge section 6 by the switching claw 78 at the first switching position. Since the guide roller 74 is rotatably supported by the ADF 1 main body, even a stiff original can be smoothly discharged while absorbing the load by the guide 74.
[0066]
Next, after the reversing / discharge motor 72 is stopped, it is determined whether or not the mode is the duplex mode (step S58). If the mode is the duplex mode, it is determined whether or not the discharge of the final document is completed (step S58). S59), it is determined whether or not a sheet reversal signal has been input (step S60). If the sheet reversal signal has been input, the process returns to the flow shown in FIG.
On the other hand, if it is determined in step S58 that the mode is not the duplex mode, the process shown in FIG. 13 is executed. That is, in step S38, it is determined whether or not there is a next original. If there is no next original, the processing from step S39 is executed. If there is a next original, the feed motor 23 is rotated clockwise in the clockwise direction. The transport belt motor 58 is driven to rotate forward in a counterclockwise direction, and the reverse / discharge motor 72 is driven forward in a counterclockwise direction. At this time, the motors 23, 58, and 72 are started up slowly, and the number of pulses of each motor is counted (step S61).
[0067]
That is, the lowermost document of the document bundle is separated from the subsequent document bundle conveyed between the separation roller 19 and the separation belt 20 by frictional separation by the separation roller 19 and the separation belt 20, and only this document is separated. 19, it is conveyed by a pull-out drive roller 20 and a pull-out driven roller 20a. At this time, the main controller 18 inputs a four-phase signal to the motor driver with a gradually shortened pulse width, thereby gradually shortening the pulse width when the coil is excited by the motor driver to feed the paper. The motor 23 is started by slow-up.
[0068]
Then, it is determined whether or not the slow-up of each of the motors 23 and 58 has been completed since the separation of the document was started (step S62). It is determined whether the leading edge of the document has been detected (step S63).
If the registration sensor 100 has not been turned on, it is determined whether or not the pulse of the paper feed motor 23 has reached the above-mentioned set value A (step S64). If it is determined that the number of pulses has reached the pulse count A, the processing shown in FIG. 14 is executed on the assumption that a jam has occurred.
[0069]
On the other hand, when it is determined in step S63 that the registration sensor 100 has been turned on, the paper feed motor 23 and the transport belt motor 58 are started at a slow speed (step S65). Next, it is determined whether or not the slowdown start of the sheet feeding motor 23 and the conveyance belt motor 58 has been completed (step S66). In step S67, it is determined whether or not the mode is the duplex mode (step S68). If the mode is not the duplex mode, it is determined whether or not a feed / discharge signal for notifying that the preceding document has been read and exposed and the document is carried out of the contact glass 2 has been input (step S69). When this signal is input, the flow shifts to the flow shown in FIG.
[0070]
On the other hand, if it is determined in step S18 in FIG. 12 that the mode is not the one-sided butting mode, the two-sided mode shown in FIG. 16 is executed. In FIG. 16, first, it is determined whether or not the discharge sensor 104 is ON (step S81). If it is determined that the discharge sensor 104 is not ON, the pulse count value of the transport belt motor 58 is set to the pulse set value D. Is determined (step S82). The pulse set value D is a value obtained by adding the jam detection allowance distance to the distance from the leading end of the document to the paper discharge sensor 104 on the contact glass 2 as described above. When it is determined that the set value D has been reached, the jam processing shown in FIG. 14 is executed, and when it is determined that the set value D has not been reached, the process returns to step S81.
[0071]
If it is determined in step S81 that the paper discharge sensor 104 has been turned on, the reversing solenoid 89 is turned on, and the transport belt motor 58 is slowed down (step S83). That is, by turning on the reversing solenoid 89, the drive shaft 88 is pulled in the direction of arrow A against the pulling force of the return spring 90, thereby switching the switching claw 78 to the second switching position and contacting the original discharge position. The position is returned to the glass 2 return position.
[0072]
Next, it is determined whether or not the slowdown start of the transport belt motor 58 has been completed (step S84). If it is determined that the slowdown start has been completed, the drive of the transport belt motor 58 is stopped (step S85). Next, the transport belt motor 58 is driven to rotate in the reverse direction in the clockwise direction, and the transport belt 53 is driven in the clockwise direction in a slow-up manner (step S86).
[0073]
Next, it is determined whether or not the slow-up of the conveyor belt motor 58 has been completed (step S87). If it is determined that the slow-up has been completed, it is determined whether or not the paper discharge sensor 104 has been turned off (step S88). If it is determined that the discharge sensor 104 has not been turned off, it is determined whether or not the pulse count of the conveyor belt motor 58 has reached the above-described pulse set value G (step S89). If it is determined that the time has arrived, the jam processing shown in FIG. 14 is executed, and if it is determined that the time has not reached, the process proceeds to step S88.
[0074]
On the other hand, if it is determined in step S88 that the paper discharge sensor 104 has been turned off, the paper discharge sensor 104 detects the rear end of the document and detects that the document has been returned to the contact glass 2. Therefore, the switching solenoid 78 is turned off to switch the switching claw 78 to the first switching position (step S90). Next, it is determined whether or not the pulse count value of the transport belt motor 58 has reached the pulse set value J (step S91). The pulse set value J is obtained by subtracting the distance required for slowing down the transport belt motor 58 from the distance from the paper discharge sensor 104 to the document stop reference position. If it is determined that the motor has arrived, the transport belt motor 58 and the reversing / discharge motor 72 are slowed down (step S92). Then, as shown in FIG. It is determined whether the slowdown has been completed (step S93).
[0075]
When it is determined that the slowdown of both motors 58 and 72 has been completed, the driving of the conveyance belt motor 58 and the reversing / discharge motor 72 is stopped (step S94), and it is determined whether or not the reversing operation has been completed. (Step S95). If it is determined that the reversing operation has been completed, the process proceeds to step S41 in FIG. 13, and if it is determined that the reversing operation has not been completed, it is determined whether or not there is a next document. (Step S96). If there is a next document, the process proceeds to step S61 in FIG. 13, and based on the detection information from the document set sensor 10, if there is no next document, the calling solenoid 17 is turned off (step S97). For this reason, the rotation shaft 103 rotates to prevent the document stopper 8 from entering the document bundle, and the pressing lever 12 is separated from the call roller 11.
[0076]
Next, it is determined whether or not an inversion signal has been input (step S98). If the inversion signal has been input, the transport belt motor 58 and the inversion / discharge motor 72 are driven forward in a slow-up manner, and both motors 58 and 72 are driven. After the counting of the number of pulses is started (step S99), the processing after step S81 shown in FIG. 16 is executed. In this case, the original is discharged with the original surface facing upward as in the state where the original is initially set on the original placing table 3 by the processing after step S81. If it is determined in step S68 in FIG. 13 that the mode is the duplex mode, the duplex mode processing from step S98 in FIG. 17 is executed.
[0077]
As described above, in the present embodiment, immediately before the image of the document is read by the reading unit, the document is abutted against the reference scale 56, and the document is then separated from the reference scale 56 by a predetermined amount a (0. (Approximately 5 to 1.0 mm) and stand by, so that it is possible to prevent the original from bending and floating from the contact glass 2 after correcting the bending or displacement of the thin original. As a result, it is possible to prevent the occurrence of contraction phenomena such as bending of lines and contraction of characters when reading the document, and it is possible to read the document normally.
[0078]
In addition, since the transport belt 53 is driven by the transport belt motor 58 composed of a pulse motor, the original is reliably separated from the reference scale 56 by a predetermined amount a as compared with a configuration in which the transport belt is driven by a DC motor having a coarse movement. The document can be accurately conveyed to a predetermined position separated from the reference scale 56.
Further, since the abutment member for correcting the orientation of the original is constituted by the reference scale 56 provided at the end of the contact glass 2, the original transport time can be shortened, and the original can be accurately positioned at the reading position. Can be done.
[0079]
That is, for example, after a stopper member or the like is provided at a predetermined position on the conveyance path of the ADF 1 to correct the posture of the document, and when the document is conveyed from this stopper member to the reading / exposing position on the contact glass 2, the document Is longer, and it is difficult to accurately position the reading position.
When the document is separated from the reference scale 56 constituting the reading reference position provided at the end of the contact glass 2 as in this embodiment, an amount corresponding to the bending of the document (0.5 to 1) .0 mm), it is only necessary to separate the document from the reference scale 56, so that the document transport time can be shortened and the document can be accurately positioned at the reading position. Further, since it is sufficient that the document is separated from the reference scale 56 by an amount corresponding to the bending, it is possible to suppress the posture of the corrected document from changing again, and it is possible to sufficiently correct the posture of the document. .
[0080]
Further, a thick paper mode and a thin paper mode are set by a mode setting switch. When the thin paper mode is set, the original is abutted against the reference scale 56, and then the original is separated by a predetermined amount a in a direction in which the original is separated from the reference scale 56. When the thick paper mode is set, the reading is performed while the original is abutted against the reference scale 56, so that the optimum transport can be performed according to the paper quality of the original. .
[0081]
That is, for a thick original such as a thick original that does not bend even when it hits the reference scale 56 because of its high strength against buckling, when the original is separated from the reference scale 56 by a predetermined amount a just before reading, There is a possibility that the orientation of the document changes by the amount.
For this reason, by controlling the transport state of the transport belt 53 as described above, in the case of a thick original, reading is performed while the original is still in contact with the reference scale 56, thereby changing the orientation of the original. In the case of a thin original, reading is performed in a state in which the original is separated from the reference scale 56 by a predetermined amount a, thereby ensuring that the original is bent and lifted up from the contact glass 2. Can be prevented.
[0082]
【The invention's effect】
According to the first aspect of the present invention, the original is abutted against the abutting member to correct the bending or misalignment of the original, and then the original is conveyed by a predetermined amount in a direction away from the abutting member. In addition, it is possible to prevent the original from bending and floating from the contact glass. As a result, it is possible to prevent the occurrence of contraction phenomena such as bending of lines and contraction of characters when reading the document, and it is possible to read the document normally.
[0083]
According to the second aspect of the present invention, the document can be reliably separated from the butting member by the predetermined amount by the conveying member driven by the pulse motor, and the document can be accurately positioned at the predetermined position where the document is separated from the butting member. Can be transported.
According to the third aspect of the present invention, the document need only be separated from the reference scale by an amount corresponding to the bending of the document, so that the transport time of the document can be shortened and the document can be accurately positioned at the reading position. Can be. Further, since it is only necessary to separate the original from the reference scale by an amount corresponding to the deflection of the original, it is possible to suppress the posture of the corrected original from fluctuating again, and it is possible to sufficiently correct the posture of the original. it can.
[0084]
According to the fourth aspect of the present invention, in the case of a thick original, the reading is performed while the original is being abutted against the abutting member, so that the posture of the original can be reliably prevented from changing. In addition, in the case of a thin original, reading is performed in a state where the original is separated from the abutting member by a predetermined amount, so that it is possible to reliably prevent the original from bending and floating from the contact glass.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an embodiment of an automatic document feeder according to the present invention.
FIG. 2 is a schematic view of a drive mechanism of the automatic document feeder according to the embodiment.
FIG. 3 is a perspective view of a document stopper, a detection filler, a call arm, and a call roller that constitute a part of the separation / conveyance means according to the embodiment.
4A is a side view of a calling arm and a pressing lever according to an embodiment, FIG. 4B is a configuration diagram of a document stopper and a detection filler, and FIG. It is a figure showing a state.
FIG. 5 is a detailed view of a separating / transporting unit according to one embodiment, showing a state in which a leading end of a bundle of originals is in contact with an original stopper.
FIG. 6 is a detailed view of a separating / transporting unit according to one embodiment, showing a state where a document stopper is separated from a leading end of a document bundle.
FIG. 7 is a configuration diagram of a transport belt unit according to one embodiment.
FIG. 8 is a perspective view of a switching claw, a reversing drive roller, and a guide roller that constitute a part of the sheet discharging means of one embodiment.
FIG. 9 is a diagram illustrating a state in which a document according to one embodiment is placed on standby by being separated from a reference scale by a predetermined amount a.
FIG. 10 is a flowchart illustrating a document conveying method according to an embodiment.
FIG. 11 is a flowchart illustrating a method of conveying a document following the flowchart of FIG. 10;
FIG. 12 is a flowchart illustrating a method of conveying a document following the flowchart of FIG. 11;
FIG. 13 is a flowchart illustrating a method of conveying a document following the flowchart of FIG. 12;
FIG. 14 is a flowchart showing an operation at the time of jam processing according to one embodiment.
FIG. 15 is a flowchart illustrating a method of conveying a document following the flowchart of FIG. 13;
FIG. 16 is a flowchart illustrating a method of conveying a document in a duplex mode according to an embodiment.
FIG. 17 is a flowchart illustrating a method of conveying a document following the flowchart of FIG. 16;
FIG. 18 is a diagram illustrating a conventional state in which a document is lifted from a contact glass.
FIG. 19 is a diagram showing exposure positions on the photosensitive drum when exposing a document floating from the contact glass and a document not floating from the contact glass.
[Explanation of symbols]
1 ADF (automatic document feeder)
2 Contact glass
3 Document placement table
5 Transport means
18 Main control unit (switching means)
51 Drive roller (transportation member)
53 Conveying belt (conveying member)
56 Reference scale (butting member)

Claims (5)

Is attached to the image reading apparatus for reading an image of a document to be stopped at the reading position on the contact glass, conveys the document fed from the sheet feeding direction and composed document table to the contact on the glass, after completion of the reading Conveying means for conveying the document in a sheet discharging direction opposite to the sheet feeding direction, a detection sensor for detecting a position of the document to be conveyed, and abutting of the document conveyed on the contact glass While correcting the orientation of the document, the abutted member serving as a reference for the reading position, and the fed document is placed on the contact glass based on the position of the document detected by the detection sensor. A control means for controlling the conveying means so as to convey the original and stop at the reading position by abutting against the abutting member, and after the reading is completed, to convey the original in the discharge direction. In the automatic document feeder with bets,
The control means has a plurality of selectable modes including a thin paper mode for transporting a thin original and a thick paper mode for transporting a thick original, and the original is transported to a predetermined position near the reading position. Then, a slowdown that decelerates in accordance with the selected mode is performed, the document is stopped at a stop position that has passed a predetermined amount from the abutting member in the discharge direction, and the document has passed the predetermined amount and has stopped at the stop position. The stopped document is conveyed in such a manner as to perform a slow-up that accelerates in accordance with the selected mode so as to return the excessively moved predetermined amount in the reverse paper feed direction, and to return the excessively moved predetermined amount. with stops at the abutment member said batten butt at the reading position at a predetermined speed corresponding to the document conveyed to the mode selected by performed the slowdown, wherein To perform the correction of draft posture, the at thin paper mode selection, so as to stand by the original stopped at the reading position is conveyed by Tokoro quantified the discharging direction so as to apart from the abutment member, wherein An automatic document feeder for controlling a feeding means . 2. The automatic document feeder according to claim 1, wherein the transfer unit includes a transfer member driven by a pulse motor. 3. The automatic document feeder according to claim 1, wherein the abutting member is a reference scale provided at an end of the contact glass and constituting a reading reference position when the end of the document abuts. apparatus. Immediately before the image of the original is read by the image reading device, the original is abutted against the abutting member, and then the original is transported by a predetermined amount in a direction away from the abutting member. The automatic document feeder according to any one of claims 1 to 3, further comprising a switching unit that switches and controls the transport unit so as to perform either one of the operation of the original and the state in which the contact is maintained. Attached to an image reading device that reads an image of a document stopped at a reading position on the contact glass, transports the document fed from the document mounting table in the feeding direction onto the contact glass, and after the reading is completed, Conveying means for conveying the document in a sheet discharging direction opposite to the sheet feeding direction, a detection sensor for detecting a position of the document to be conveyed, and abutting of the document conveyed on the contact glass While correcting the posture of the original, the abutted member serving as a reference of the reading position, and based on the position of the original detected by the detection sensor, the fed original is placed on the contact glass. A control means for controlling the conveying means so as to convey the original and stop at the reading position by abutting against the abutting member, and after the reading is completed, to convey the original in the discharge direction. The control method of the automatic document feeder with bets,
The control means has a plurality of selectable modes including a thin paper mode for transporting a thin original and a thick paper mode for transporting a thick original, and the original is transported to a predetermined position near the reading position. And performing a slowdown that decelerates in accordance with the selected mode, and stopping the original at a stop position that has passed a predetermined amount from the abutting member in the discharge direction. And causing the document stopped at the stop position after passing the predetermined amount to perform a slow-up in which the document is accelerated in accordance with the selected mode, and to convey the document so as to return the predetermined amount that has gone too far in the sheet feeding direction in the opposite direction. Stopping the original conveyed so as to return the excessive amount by a predetermined speed corresponding to the selected mode by performing the slowdown and stopping at the reading position. Correcting the orientation of the document, and, when the thin paper mode is selected, transporting the document stopped at the reading position by a predetermined amount in the sheet discharging direction so as to be separated from the abutting member and stand by. And a step of controlling the conveying means.

Images