JP4688692B2 - Paper sheet conveying apparatus and driving method of paper sheet conveying apparatus - Google Patents

Description

  The present invention relates to a paper sheet conveying apparatus in an image forming apparatus or the like and a driving method thereof.

  A paper sheet conveying device and a driving method thereof in a conventional image forming apparatus and the like are disclosed in Patent Document 1 described later.

  This document relates to “a reversing type duplex document feeding apparatus and image reading apparatus”. This “original conveying apparatus and image reading apparatus” is for preventing the trailing edge of the original from being caught when the paper discharge roller is rotated in the reverse direction in the apparatus initialization operation after the final page is discharged.

  This reversing duplex scanning device is located at the upstream of the branching claw and the branching claw for switching whether to guide the leading edge of the original after single-sided scanning to the reversing part for switching back or to the discharge stack part. And a paper discharge roller for carrying out the conveyance to the reversing unit and the paper discharge operation.

  In this reversing double-sided reading device, when a series of reading operations are completed or stopped, the discharge stack unit side is used to prevent wrapping during reverse rotation during the reverse rotation operation of the discharge roller by the device initialization operation performed after the final page is discharged. The branching portion that guides to is switched to a position that guides to the reversing portion.

Solenoids are often used as drive means for driving the above-mentioned branching claws. The solenoid attracts the plunger by energizing the coil, and when the energization is turned off, the plunger is returned to its original position by an external force such as a spring to operate the transfer path switching claw and the like.
JP 2005-86217 A

  By the way, the energization time to the solenoid that drives the branching claw varies depending on the conveyance length of the paper sheet. And when the energization time to the coil is long, the heat generation of the solenoid increases. Therefore, in order to suppress the heat generation of the solenoid, the coil is energized by chopping driving performed by duty control such as PWM control.

  However, when PWM control is performed on the solenoid, it is necessary to reduce the chopping drive sound due to the vibration of the solenoid, and the frequency of the chopping drive sound and the natural vibration of the machine so that the solenoid and the machine do not resonate. It is necessary to consider that the number does not match.

  The present invention has been made paying attention to such a problem, and it is possible to change the duty drive cycle of the solenoid, and control the machine so that the natural frequency of the machine and the duty drive cycle do not coincide with each other. The object is to reduce the sound and resonance sound.

In order to solve the above-described problem, a paper sheet transport apparatus according to claim 1 of the present application includes:
A plurality of transport paths for transporting the paper sheet, path switching means for switching the transport destination of the paper sheet relative to the transport path, and a solenoid for performing a switching operation of the path switching means, The solenoid includes a movable iron core that performs the switching operation of the path switching means, a spring that positions the movable iron core at a predetermined position, and a coil that drives the movable iron core against the elastic force of the spring. A conveying device,
Energization control means for duty-driving the coil with a pulse current within a range in which the force for guiding the movable iron core does not decrease with respect to the elastic force of the spring, and the paper sheet conveyed in the conveyance path is detected. A sheet detection unit, and the energization control unit starts duty drive control of the coil based on information detected by the sheet detection unit and detects the duty drive chopping. The ratio between the ON period and the chopping OFF period is varied for each cycle .

The driving method of the paper sheet conveying apparatus according to claim 2 of the present application is as follows:
In the driving method of the paper sheet conveying apparatus according to claim 1,
The energization control unit varies the ratio between the chopping ON period and the chopping OFF period so as to be different from a driving frequency of a motor used for transporting the paper sheet .

The driving method of the paper sheet conveying apparatus according to claim 3 of the present application is as follows:
In the driving method of the paper sheet conveying apparatus according to claim 1 ,
The energization control unit varies the ratio of the chopping ON period and the chopping OFF period so as to be different from the meshing frequency of the driving gear of the driving unit that conveys the paper sheet .

The driving method of the paper sheet conveying apparatus according to claim 4 of the present application is as follows:
In the driving method of the paper sheet conveying apparatus according to claim 1 ,
The energization control unit varies the ratio of the chopping ON period and the chopping OFF period so as to be different from the natural frequency of the spring of the path switching unit .

The driving method of the paper sheet conveying apparatus according to claim 5 of the present application is as follows:
In the driving method of the paper sheet conveying apparatus according to claim 1 ,
The energization control unit varies the ratio between the chopping ON period and the chopping OFF period so as to be different from the natural frequency of the entire path switching unit .

The driving method of the paper sheet conveying apparatus according to claim 6 of the present application is as follows:
In the driving method of the paper sheet conveying apparatus according to claim 1 ,
The energization control unit varies the ratio of the chopping ON period and the chopping OFF period using a random number table .

The driving method of the paper sheet conveying apparatus according to claim 7 of the present application is as follows:
In the driving method of the paper sheet conveying apparatus according to claim 1 ,
The energization control unit varies the ratio between the chopping ON period and the chopping OFF period using random number data set based on the sheet conveyance length detection result .

The driving method of the paper sheet conveying apparatus according to claim 8 of the present application is as follows:
In the driving method of the paper sheet conveying apparatus according to claim 1 ,
The energization control unit varies the ratio between the chopping ON period and the chopping OFF period by varying only the chopping ON period within one cycle of the duty drive .

The driving method of the paper sheet conveying apparatus according to claim 9 of the present application is as follows:
In the driving method of the paper sheet conveying apparatus according to claim 1 ,
The energization control means varies the ratio of the chopping ON period and the chopping OFF period by varying only the chopping OFF period within one cycle of the duty drive .

  According to the paper sheet conveying apparatus of claim 1 of the present invention, the energization control means starts the duty drive control of the coil based on the information detected by the paper sheet detecting means that the paper sheet has been conveyed. Therefore, since the start timing of energization to the solenoid is optimized, the heat generation of the coil is suppressed, and the temperature rise of the solenoid can be suppressed without requiring a special configuration for preventing the heat generation, resulting in an increase in cost. Can be prevented. In addition, since the duty drive control is performed after detecting the conveyed paper sheet and the drive time is short, the chopping drive sound of the solenoid can be reduced.

Also, by changing the ratio of the duty-driven chopping ON period and the chopping OFF period for each cycle, the frequency of the beat sound generated during chopping drive can be diffused to avoid resonance with the device body, and noise Can be reduced.

Furthermore, even when the solenoid energization time is short, the resonance with the frequency of other devices such as the device main body and the motor can be avoided by spreading the drive frequency, and a noise reduction effect can be obtained.

According to the driving method of the paper sheet conveying apparatus of claim 2 of the present invention, the motor and the solenoid are prevented from resonating, and noise can be reduced.

According to the driving method of the paper sheet conveying apparatus of the third aspect of the present invention, resonance with the sound of the gear is prevented, and resonance with the noise generated from the drive system can be prevented.

According to the driving method of the sheet conveying apparatus of claim 4 of the present invention, resonance with the spring that drives the switching means is prevented, and noise due to resonance with the spring can be reduced.

According to the driving method of the paper sheet conveying apparatus of claim 5 of the present invention, it is possible to prevent an increase in noise due to resonance with the natural frequency of the entire apparatus.

According to the driving method of the paper sheet conveying apparatus of claim 6 of the present invention, the energization control means varies the ratio of the chopping ON period and the chopping OFF period using the random number table, so that the probability of resonance decreases. Generation of noise can be prevented without being conscious of resonance with other components.

According to the driving method of the sheet transport apparatus of claim 7 of the present invention, the ratio between the chopping ON period and the chopping OFF period is changed using random number data set based on the sheet transport length detection result . The periodic fluctuation rate of the solenoid can be determined at random according to the conveyance length of the paper sheet, the noise generation probability of the solenoid can be lowered, and even if noise occurs, the time can be shortened. .

According to the driving method of the paper sheet conveying apparatus of claim 8 of the present invention, only the period of chopping ON (positive voltage application) is changed in one cycle of duty driving, so that the suction force can be maintained at a certain level or more .

According to the driving method of the sheet transport apparatus of claim 9 of the present invention, since only the chopping OFF (0 level) period is changed in one cycle of the duty driving, the suction force during the ON period is stabilized. Can do.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a paper sheet conveying apparatus and a driving method thereof according to the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 shows an automatic document feeder (hereinafter referred to as an ADF (Automatic Draft Feeder) device) as an example of a paper sheet feeder according to an embodiment of the present invention. Reference numeral 200 indicates an ADF apparatus. The ADF apparatus 200 is mounted on an image forming apparatus such as a copying machine having a printer function, a scanner function, and the like. Recently, some facsimiles are provided with a copy and printer function, and such a facsimile can be interpreted as an image forming apparatus. The paper sheet is a document in this embodiment.

In FIG. 1, reference numeral 0 is a document bundle, 1 is a document table, 2 is a stop claw, 3 is a pickup roller, 4 is a reverse roller, 5 is a paper feed belt, 6 is a pull-out roller, 7 is a driven roller, and 8 is a reading entrance roller. , 9 is a driven roller, 10 is a reading exit roller, 11 is a driven roller, 12 is a paper discharge roller, 13 is a driven roller, 14 is a paper discharge tray, 15 is a switching claw, 16 is a reversing roller, 17 is its driven roller, 18 is an upper driven roller of the paper discharge roller 12, 19 is a document set sensor, 20 to 22 are document length sensors provided on the document table 1, 23 is a separation sensor, 24 is an abutment sensor, 25 is a document width sensor, and 26 is A reading entrance sensor, 27 is a registration sensor, 28 is a document sensor, 29 is a paper discharge port sensor, 30 is a reading exit sensor, 31 is a document set filler, and 40 is a guide for guiding a document. Plate, glass 41 for placing a document, 42 is a guide plate for guiding the document glass 41.

  The image forming apparatus includes an ADF apparatus 200, a document table 1 (document mounting unit) on which a document to be read (hereinafter simply referred to as a document), and a document placed on the glass 41 and radiating light from below the glass 41. An unillustrated document reading unit that projects reflected light from the document onto a photosensitive member or the like through an optical system (not shown) to form an electrostatic latent image of the document on the photosensitive member, and an electrostatic latent image on the photosensitive member of the document reading unit A fixing unit (not shown) that transfers the toner to a copy sheet after the toner is attached to the sheet and heat-fixes it, and a copy sheet mounting unit (not shown) that mounts a paper sheet on which an image of the original from the fixing unit is fixed. And a paper discharge tray 14 for stacking the read originals. Since the document reading unit, transfer / fixing unit, copy paper mounting unit, document mounting unit, and the like are well known in the copying apparatus and printer apparatus, description thereof will be omitted.

  The ADF apparatus 200 includes a document table 1 on which a document is mounted. A document bundle 0 to be read is mounted on the document table 1. One end side of the document table 1 is open so that the document is fed, and a pickup roller 3 for taking out the documents one by one from the upper side of the document bundle 0 is vertically moved on the document table 1. It is arranged to be movable. A document set filler 31 that aligns the end portion is rotatably provided at a portion of the document table 1 where the document comes out.

  The original in the original bundle 0 is in a state where the surface on which characters, figures, etc. are written (the front page side in the case of a double-sided original) faces upward, and the front end of the original is abutted against the stop claw 2. set. The stop pawl 2 protrudes on the guide plate 60 and stands by so as to receive the original document bundle 0 at the normal time.

  When the document bundle 0 is set on the stop claw 2, the document set filler 31 is pushed by the document bundle 0 and changes its angle from the broken line state to the solid line state in FIG.

  The stop pawl 2 can be turned up and down around a mounting shaft 2 </ b> A extending in the width direction of the guide plate 60. The mounting shaft 2 </ b> A is rotated in the vertical direction by the calling motor 101 of FIG. 2 arranged below the guide plate 60. The rising of the document set filler 31 is detected by the document set sensor 19, and the setting of the document bundle 0 is detected.

  When the document setting sensor 19 detects the rising of the document setting filler 31, the stop pawl 2 can be lowered. When a print key is pressed from a main body operation unit (not shown) of the image forming apparatus and a document feed signal is transmitted from the main body control unit 111 shown in FIG. 2 to the ADF apparatus 200, the calling motor 101 is driven to rotate forward to stop the pawl. Retract 2 downward (solid line). The retraction of the stop claw 2 is detected by a claw home position sensor 34 (see FIG. 2). When the stop claw 2 is lowered and detected by the claw home position sensor 34, the calling motor 101 is driven in reverse to lower the pickup roller 3 so as to hold the document bundle 0 from above.

  The document table 1 is provided with document length sensors 20 to 22 for detecting the document length, and the document length sensors 20 to 22 roughly determine the length of the document in the conveyance direction. The document length sensors 20 to 22 are arranged so as to be able to determine at least whether the document has a vertical or horizontal size. The detection information of the document length sensors 20 to 22 is used to roughly determine the document size based on a combination with a document width detection result described later. Note that both ends of the document bundle 0 in the width direction are positioned in a direction perpendicular to the document conveyance direction by a side fence (not shown).

  Reference numeral 60 denotes a guide plate for conveying a document received from the document table 1. The guide plate 60 switches the running path when switching the front and back of the document. The upper running path 60A of the guide plate 60 is used when reading the front side of the document, and the conveyance path 60B of the guide plate 60 is the back side of the document. Is used for back-and-front alignment processing when reading and after back side reading. An opening through which the stop claw 2 enters and exits is formed on the document receiving side of the guide plate 60. Reference numeral 61 denotes a housing upper housing of the ADF apparatus 200. A pickup roller 3 is arranged on the upper part of the housing upper housing 61 so as to be movable up and down. An opening (not shown) for moving the pickup roller 3 up and down is formed in the vicinity of the document receiving port of the upper housing 61. Both ends of the pickup roller 3 are rotatably held by levers (not shown). A drive source for moving the pickup roller 3 up and down is a call motor 101, and a mechanism for moving the pickup roller 3 up and down by the call motor 101 is not shown.

  In FIG. 1, the movable regions of the pickup roller 3 and the document set filler 31 are shown overlapping, but a ring-shaped groove is provided in a part of the outer peripheral portion of the pickup roller 3, and the document set filler 31 is It is formed so as to be able to pass through the groove, and the document set filler 31 and the pickup roller 3 do not interfere with each other. The document set filler 31 is directed downward in a normal state. When the document bundle 0 of the document table 1 is sent to the stop claw 2, the document set filler 31 is rotated and moved onto the document bundle 0 to reach the top of the document bundle 0. The upper document can be conveyed.

  Reference numeral 62 denotes a document separating portion bulging and formed on the guide plate 60. The end of the document bundle 0 is applied to the slope of the document separating portion 62 so as to roll the upper and lower document bundles 0 to prevent the originals from overlapping each other. Yes. An opening (not shown) extending in the axial direction of the reverse roller 4 is formed at the uppermost portion of the document separating section 62, and the outer peripheral surface of the reverse roller 4 is exposed on the document separating section 62 from this opening. A paper feed belt 5 is provided on the reverse roller 4. The paper feed belt 5 is stretched between a pair of transport rollers 5A and 5B.

  The transport rollers 5A and 5B are rotated by the paper feed motor 102 in FIG. 2 via a power transmission mechanism (not shown). The transport rollers 5A and 5B rotate in a direction to send out the document sent by the pickup roller 3 in the moving direction. The paper feed belt 5 sends out one original document fed by the rotation of the conveying rollers 5A and 5B to the pull-out roller 6 and the driven roller 7 on the downstream side. The reverse roller 4 is rotated by the paper feed motor 102 via the power transmission mechanism and a reverse rotation gear. The reverse roller 4 rotates in the direction opposite to that of the paper feeding belt 5, and when the two originals are sent in a stacked manner, the lower original is returned to the original table 1 side.

  The document separation unit 62 protrudes upward to prevent the two-sheet document from overlapping. A pull-out roller 6 and a driven roller 7 are disposed on the downstream side of the document separation unit 62. The pull-out roller 6 and the driven roller 7 pull out the document sent from the document separation unit 62. Reference numeral 23 denotes a separation sensor, which checks whether or not the separation sensor is separated. Reference numeral 24 denotes an abutting sensor. The abutting sensor 24 detects the leading edge of the document and outputs it to the CPU 50 of the controller 100 (see FIG. 8). The controller 100 stops the paper feed motor 102 after conveying the document by a predetermined amount X mm after the abutting sensor 24 detects the leading edge of the document.

  A guide plate 63 having a bowl-shaped cross section is disposed below the housing upper housing 61 and downstream of the document separation unit 62. The pull-out roller 6 and the driven roller 7 are exposed from an opening formed in the guide plate 63, and the peripheral surfaces of the pull-out roller 6 and the driven roller 7 are in contact with each other. Document width sensors 25 that detect the width of the document are provided on the left and right sides of the guide plate 63.

  The pull-out roller 6 has a skew correction function for a document bent by the reverse roller 4. The pull-out roller 6 is a roller for conveying the skew-corrected document after being separated from the sheet feeding belt 5 to the reading entrance roller 8 and is driven by the reverse rotation of the sheet feeding motor 102.

  The pickup roller 3 is driven to rotate in the direction in which the uppermost document is conveyed to the sheet feeding port by the normal rotation of the sheet feeding motor 102, and several sheets (ideally one sheet) on the document table 1 are fed to the sheet feeding belt. 5 and a reverse roller 4 are fed to a document separation unit 62. The sheet feeding belt 5 is driven in the sheet feeding direction by the forward rotation of the sheet feeding motor 102, and the reverse roller 4 is driven to rotate in the direction opposite to the sheet feeding.

  As a result, the top document and the document below it are separated, and only the top document is fed. The original separated by the action of the paper feed belt 5 and the reverse roller 4 is further fed by the paper feed belt 5, and the original is conveyed by a predetermined amount of Xmm from the time when the leading edge is detected by the abutting sensor 24. The forward drive of the motor 102 is stopped. At this time, by making the above-mentioned predetermined amount Xmm larger than the distance from the abutting sensor 24 to the pull-out roller 6, the document is stopped in a state in which the pull-out roller 6 is formed with a certain amount of bending.

  At this time, the pick-up roller 3 is retracted from the upper surface of the original by reversing the calling motor 101, and the original is sent only by the conveying force of the paper feed belt 5. As a result, the leading edge of the document enters the nip between the pull-out roller 6 and the driven roller 7, and the bending (skew) of the document that occurs during separation feeding can be corrected.

  Note that if the transition time from the forward rotation to the reverse rotation of the paper feed motor 102 is shortened, the document feed time is shortened and the productivity is improved. Consider the possibility of creating a key. For this reason, current switching is effectively performed when the paper feed motor 102 is driven forward and reverse. This makes it possible to reduce noise while ensuring the success rate of document reading.

  The transmission mechanism between the paper feed motor 102 and the paper feed belt 5 is provided with a one-way clutch, and the pull-out roller 6 is driven when the paper feed motor 102 rotates in the reverse direction. The paper belt 5 is not driven.

  A document width sensor 25 that detects the width of the document is disposed on the downstream side of the pull-out roller 6. A plurality of document width sensors 25 are provided in the document width direction, that is, in the direction orthogonal to the document transport direction. The document width sensor 25 is composed of, for example, a lever-like switch that protrudes into the document transport path 64 and is moved upward by being pushed by the document. When the document width sensor 25 comes into contact with the document when it is transported, it moves over the document and turns on. The document width is detected by the difference in the installation position of the document width sensor 25 that is turned on. The length information of the document width detected by the document width sensor 25 and the length information of the document read by the sensors 20 to 22 on the document table 1 are transmitted to the controller 100, and the controller 100 combines the two information. Thus, the size of the document bundle 0 stacked on the document table 1 is determined.

  A reading entrance sensor 26 is provided further downstream of the document width sensor 25. A space between the guide plates 42 and 43 located below the reading entrance sensor 26 is a conveyance path 44 for reading a document, and a reading inlet roller 8 is disposed in the conveyance path 44. When the leading edge of the document passing through the conveyance path 64 on the guide plate 63 is detected by the reading entrance sensor 26, the deceleration starts before the leading edge of the document enters the reading entrance roller 8 and the driven roller 9.

  Here, when the paper feed motor 102 that drives the pull-out roller 6 is stopped so that the transport distance is longer by Y mm than the distance from the reading inlet sensor 26 to the reading inlet roller 8 and the driven roller 9, it is stopped. The leading edge of the document comes into contact with the nip portion between the reading entrance roller 8 and the driven roller 9 and the document is stopped in a state where a certain amount of deflection is formed, and the skew generated when the document is conveyed by the pull-out roller 6 can be corrected.

  The registration sensor 27 detects that the document is temporarily stopped (resist stop) at the nip portion between the reading entrance roller 8 and the driven roller 9. The registration sensor 27 transmits a registration stop signal to the CPU of the controller 100 via the interface circuit.

  The exact length in the document transport direction is calculated by multiplying the number of motor drive pulses counted during the period in which the abutting sensor 24 detects the leading edge and the trailing edge of the document and the document transport amount per pulse.

  When the document is transported to the reading entrance roller 8 by the pull-out roller 6, the processing time for feeding the document to the reading unit by setting the document transport speed to a high speed is shortened, and particularly for the second and subsequent documents. By reducing the distance between the paper and the previous document by this high-speed conveyance, the document reading time can be shortened and the productivity can be improved.

  When the leading edge of the document is detected by the reading inlet sensor 26, the controller 100 starts decelerating before the leading edge of the document enters the reading inlet roller 8. Here, the paper feed motor 102 is stopped so that the transport distance is longer by Y mm than the distance from the reading entrance sensor 26 to the reading entrance roller 8.

  As a result, the leading edge of the document comes into contact with the nip portion of the reading entrance roller 8 that is stopped, and the document is stopped in a state where a certain amount of deflection is formed, and the skew generated when the document is conveyed by the pull-out roller 6 can be corrected. When the original is temporarily stopped (resist stop) at the nip portion of the reading entrance roller 8, the registration sensor 27 transmits a registration stop signal to the controller 100 via the interface circuit 107.

  Subsequently, when the controller 100 receives a reading start signal from the main body control unit 111, the document reading operation starts. By starting the document reading operation, the reading motor 103 is driven to rotate forward, and the reading inlet roller 8 and the reading outlet roller 10 are driven at a conveyance speed corresponding to the reading magnification. In this case, when the leading edge of the document is detected by the registration sensor 27, the pulse count of the reading motor 103 is started, and the main controller 111 is sub-scanned at the timing when the leading edge of the document reaches the document sensor 28 of the document reading unit. A gate signal indicating the effective image area in the direction (original transport direction) is sent out. The gate signal is normally sent until the trailing edge of the document passes through the document sensor 28 of the reading unit. The document that has passed through the document sensor 28 of the reading unit is conveyed by the reading exit roller 10 and the discharge roller 12 in the direction of the arrow A in FIG.

  When the original is a double-sided original (in the case of double-sided reading mode), the front end in the conveyance direction of the original that has passed through the original sensor 28 of the reading unit during front side reading reaches the reading exit sensor 30 before reaching the paper discharge roller 12. 2, the reverse solenoid 105 (see FIG. 2) in FIG. 2 is turned on.

  The reversing solenoid 105 is provided in the vicinity of the switching claw 15. A cylindrical fixed casing portion of the reversing solenoid 105 is fixed to the chassis of the ADF device 200. A plunger serving as a movable iron core is built into the cylindrical casing portion of the reversing solenoid 105. A coil for driving the movable iron core of the plunger is provided inside the fixed housing portion, and the movable iron core is connected to the switching claw 15 via a wire and a spring (not shown). A spring is biased so as to be conveyed to the paper discharge tray 14. The reversing solenoid 105 is driven by energizing the coil so that the switching claw 15 closes the conveying direction A and opens the conveying direction B, and by cutting off the energization of the coil, the switching claw 15 is driven by the spring force. It is driven to open the transport direction A and close the transport direction B. A power supply circuit for energizing the coil is provided in the controller 100. An example of a solenoid drive circuit is shown in FIG.

Current is applied to the coil of the reversing solenoid 105, to open the transport direction B block the conveyance direction A, by the plunger drives the switching claw 15, changeover pawl 15 changes over to the position of two-dot chain line The paper is conveyed in the B direction by the paper discharge roller 12 and the lower driven roller 13 driven by the reading motor 103 in FIG. 2, and the reverse roller 16 and the driven roller 17 driven by the reverse motor 104 in FIG.

When the trailing edge of the document conveyed in the direction B passes through the paper discharge roller 12, that is, after a predetermined pulse after the reading outlet sensor 30 detects the trailing edge of the document, the controller 100 turns off the reverse solenoid 105 and turns it off. returns the conversion pawl 15 to the solid line position, it opens the passage in the conveying direction a. Further, after a predetermined pulse, the reverse roller 16 is reversely rotated by the reverse drive of the reverse motor 104 to switch back the document to the conveyance path 60B (C direction) under the guide plate 60.

The driving direction of the reading motor 103 is the same direction, and the driving direction of the reversing motor 104 is the reverse direction. When the document starts to switch back, the feed motor 102 is driven at a high speed in the reverse direction, that is, the direction in which the document is fed to the reading entrance sensor 26 side by the pull-out roller 6 after a predetermined pulse.

  The document switched back by the reversing roller 16 and the driven roller 17 is conveyed in the C direction by the paper discharge roller 12 and the upper driven roller 18, and for reading the back side through the pull-out roller 6 and the reading inlet roller 8 as in the case of one side. At the nip portion of the reading entrance roller 8, it temporarily stops.

  In order to perform skew correction by abutting the leading end of the document against the nip portion of the reading entrance roller 8 even when reading the back side, the driving of the reading motor 103 needs to be stopped before the leading end of the document reaches the reading entrance roller 8. There is. For this reason, the reading motor 103 stops driving when the leading edge of the document is detected by the reading inlet sensor 26.

  The original whose registration has been stopped for reading on the back side is conveyed to the reading position at the conveyance speed corresponding to the designated magnification after receiving the reading start signal, as in the case of reading on the front side. The original moved on the glass 41 is read by the transfer unit through the glass 41 and the optical system on the back side of the original. When the reading of the back side of the document is completed, the same reversing operation for page alignment is performed again. That is, since the pages of the original bundle 0 are reversed in order when they are sent to the paper discharge tray 14 as they are, they are again passed through the transport paths 60B, 64, and 44 at a high speed and discharged to the paper discharge tray 14 by the paper discharge rollers 12.

  At the time of reversing operation for page alignment, it is not necessary to transport at a speed corresponding to the scanning magnification, so the scanning position is allowed to pass while maintaining high-speed transport, and if the trailing edge of the document is detected by the paper exit sensor 29, the speed is reduced. As a result, it is possible to prevent the document from being ejected when the document is discharged and to shorten the processing time.

  Next, the operation of the ADF apparatus will be described with reference to FIGS. FIG. 3 shows the flow of the feeding start operation.

In step s100, the document set sensor 19 determines the document set by detecting the rise of the document set filler 31 at the start of feeding. When the document setting is completed, the print key of the main body operation unit is pressed, and as described above, when the main body control unit 111 transmits a document feed signal to the ADF device 200, the calling motor 101 is driven to rotate forward at step s101. At the same time (flow S1), the stop pawl 2 is retracted downward (solid line state). When the stop claw 2 is lowered and detected by the claw home position sensor 34 (step s102), the flow proceeds to the flow S2. In the flow S2, the calling motor 101 is reversely driven (step s103), and the pickup roller 3 is lowered so as to hold the document bundle 0 from above. When it is detected that the pickup roller 3 is lowered and presses the original bundle 0 ( step s104), the calling motor 101 is stopped (step s105).

  Next, the flow proceeds to flow S3. After acquiring the document length information by the sensors 20 to 22 (s106), the controller 100 causes the paper feed motor 102 to rotate forward (s107). Since the document is conveyed by the rotation of the paper feed motor 102, it is checked whether or not the abutting sensor 24 is turned on within a predetermined time (s108). If the abutting sensor 24 is turned on within the predetermined time, the elapsed time of the abutting is determined. Start (s111). If the abutting sensor 24 exceeds a predetermined time, it is treated as a jam occurrence (s109, s110).

  After s111, the calling motor 101 is reversely rotated (s112), and the pickup roller 3 is retracted. When the pickup roller 3 is retracted (s113), the process proceeds to step S5, the calling motor 101 is stopped (s114), and it is checked whether the count value after the abutting sensor 24 is turned on is a predetermined pulse (s115). If the abutting amount has passed a predetermined pulse (s115), the current switching control is turned on, and the paper feed motor 102 is rotated in the reverse direction to carry at high speed (S116). As a result, the document is conveyed at high speed. After the document is conveyed at high speed, the ON state of the document width sensor 25 is checked (S117), and the document width information is acquired when the document width sensor 25 matching the width of the document is ON (s118) (flow S6). After obtaining the document width, it is checked whether or not it is a mixed loading mode in which originals of different sizes are mixed (S119). If the mixed loading mode is selected, the original size is transmitted to a copy paper feeding unit or a transfer unit for sending copy paper. (s120).

  After passing the document width sensor 25, it is checked whether the reading entrance sensor 26 is on (s121). If the predetermined time elapses without the reading entrance sensor 26 being turned on (s122), it is determined that a jam has occurred and jamming is performed because the leading edge of the document has not reached (s123). When the reading entrance sensor 26 is turned on, the correction count is started (flow S7) (s124). If the correction count is a predetermined pulse, the paper feed motor 102 is stopped, a registration stop is transmitted (s125), and the process returns.

  FIG. 5 shows a flow of reading processing. Next to the reading start, it is checked whether or not the mode is the single-sided mode (s200). If it is the single-sided mode, the speed of the reading motor 103 in the flow S8 is set from the reading magnification (s201). When not in the single-sided mode, the double-sided processing mode in FIG. 6 is executed.

  In the single-sided mode, after setting the reading magnification (s201), the reading motor 103 is rotated forward (s202), and it is checked whether the registration sensor 27 is on (s203). If the registration sensor 27 is on, the pulse count of the reading motor 103 is started (s204). It is checked whether or not the count value of the reading motor 103 has reached a predetermined pulse for performing surface reading (s205), and further, it is checked whether or not a correction pulse has reached a predetermined pulse for surface reading. (s206). If the surface reading pulse and the correction pulse have reached predetermined pulses in this check, a command to turn on the surface ADF gate of the switching claw 15 and open the direction of the paper discharge tray 14 is transmitted (s207). Thereafter, the surface gate count is started (s208). After the surface gate count is started, it is checked whether or not the sheet discharge outlet sensor 29 is ON (s209). When the paper discharge outlet sensor 29 is not turned on within a predetermined time (s210), it is considered that the original is not discharged into the paper discharge tray 14 and a jam has occurred, so a jam generation process is performed (s211). If the discharge port sensor 29 is turned on within a predetermined time, the flow proceeds to the flow of the connector C in FIG.

  In the process flow starting from the connector C in FIG. 5, it is checked whether or not the registration sensor 27 is OFF in S212. Next, when the registration sensor 27 is not OFF within a predetermined time (s213), Jam processing is performed (s214). When the registration sensor 27 is turned off within a predetermined time, counting for detecting the trailing edge of the read document is started (s215). As a result, the count for determining whether or not the read original is discharged is started. If the count value of the read original coincides with the predetermined pulse at the time of front side reading (s216), it is checked in flow S11 whether the gate count value for opening the gate is equal to or greater than the original length (s217). ). When the gate count value is equal to or longer than the document length, a signal for turning off the front document gate of the switching claw 15 is transmitted (s218).

  Thereafter, it is checked whether or not the paper discharge outlet sensor 29 is turned off within a predetermined time (s219). When the paper outlet sensor 29 is turned off after a predetermined time (s220), jam processing is performed (s221), and within a predetermined time. When it is OFF, the fact that the document is discharged and the discharge is completed is transmitted to the main body control unit 111 (s222), and the process returns.

  FIG. 6 shows processing in the duplex reading mode. If it is determined that the duplex mode is selected instead of the simplex mode after the document reading in FIG. 5 is started, the flow of the connector D in FIG. 6 is executed. In the case of double-sided original reading processing, first, the reading motor speed is set in accordance with the reading magnification of the surface to be read (s223). Next, the reading motor 103 is rotated forward to start counting for detecting the leading edge of the document (s224). The detection of the leading edge of the document for reading the back side is the same as the processing up to the flow S9 in FIG.

  That is, the reading motor 103 is rotated forward to check whether the registration sensor 27 is turned on. If the registration sensor 27 is turned on, the pulse count of the reading motor 103 is started. It is checked whether the count value of the reading motor 103 has reached a predetermined pulse for reading the back surface (s225), and further, it is checked whether the correction pulse has reached the predetermined pulse for reading the front surface. (s226). If the back surface reading pulse and the correction pulse have reached the predetermined pulse in this check, a command to turn on the back surface ADF gate and open the passage in the reverse conveyance direction B is transmitted (s227), and the back surface gate count is started (s228). ). After the backside gate count is started, it is checked whether or not the paper discharge port sensor 29 is ON (s229). When the paper discharge outlet sensor 29 is not turned on within a predetermined time (s230), it is considered that a jam has occurred without being conveyed to the reversing path, and a jam generation process is performed (s231). When the discharge port sensor 29 is turned on within a predetermined time, the reverse solenoid 105 is turned on (the duty drive control flag of the reverse solenoid 105 is turned on) in the flow S13, and the switching claw 15 is raised upward to open the reverse passage B side. Then, the reverse motor 104 is rotated in the normal direction to rotate the reverse roller 16 in the normal direction (s232) (flow S13).

In this flow S13, in the case of a double-sided document, when the front surface of the document is read, if the leading edge of the document that has passed through the glass 41 is detected by the discharge port sensor 29 before reaching the discharge roller 12 and the lower driven roller 13, The reverse solenoid 105 is turned on. By ON of the inversion solenoid 105, changeover claws 15 is switched to the position of two-dot chain line. The two-sided original is conveyed in the B direction by the paper discharge roller 12 and the lower driven roller 13 driven by the reading motor 103, and the reverse roller 16 and the driven roller 17 driven by the reverse motor 104. Further, the leading edge of the double-sided document conveyed in the B direction is detected by the reading outlet sensor 30 within a predetermined time (s233), and if the reading outlet sensor 30 is not turned on within the predetermined time at S233, jam processing is performed (s234, s235). If the registration sensor 27 is OFF within the predetermined time, the rear end detection is started (s236).

When the double-sided original is sent normally without jamming (s237, s238), the trailing edge detection count starts (s239), and this count matches the predetermined pulse (original length) on the back (s239) When the gate count value is equal to or longer than the document length (s240), the trailing edge of the document passes through the paper discharge roller 12 and the lower driven roller 13. When the gate count value is larger than the document length (s241), a DF gate OFF command is transmitted (s242). Next, it is checked whether or not the discharge port sensor 29 is turned off within a predetermined time (s243). If the paper outlet sensor 29 is not turned off within a predetermined time, jam processing is performed (s244, s245).

  If the paper discharge outlet sensor 29 is turned off within a predetermined time, the trailing edge of the document has passed through the paper discharge outlet sensor 29, so that a predetermined pulse is further conveyed. When the predetermined pulse is conveyed (s246), a DF gate OFF command is transmitted to stop energization of the reverse solenoid 105 (reverse solenoid duty drive control OFF) (s247), and the switching claw 15 is returned to the solid line position (flow) S14). In this flow S14, after the predetermined pulse (s248), the reverse motor 104 is reversely rotated to reversely rotate the reverse roller 16 (s249). As a result, the double-sided document sandwiched between the reversing roller 16 and the upper driven roller 18 is switched back in the C direction. In the flow S14, the reading motor 103 is driven in the same direction, and the reversing motor 104 is driven in the opposite direction.

  That is, after the flow 14, the reversing motor 104 and the reading motor 103 are driven at a high speed in order to shorten the processing time, and when the document starts to switch back, the paper feeding motor 102 is reversed in the direction to drive the pull-out roller 6 after a predetermined pulse. Rotate and drive at high speed (s249). Thereafter, the double-sided document that has been switched back is conveyed in the C direction by the paper discharge roller 12 and the upper driven roller 18, so that the flow of the connector F in FIG. 7 is executed.

  FIG. 7 shows a flow after the connector F in FIG. When the double-sided original is sent again by the pull-out roller 6 and the reading exit sensor 30 is turned off to detect the trailing edge of the original (s250), the reversing motor 104 is stopped (s251). Thereafter, the back side document reading in the flow S16 is performed. This flow S16 starts from a check of completion of reading of the back side document (s252). In the double-sided document reading mode, it goes without saying that the document on the back side is read after reading the document on the front side. In this case, first, after the back side scanning completion check is performed (s252), if the back side document is not completed, it is checked whether the reading entrance sensor 26 is ON within a predetermined time (s253). If the reading entrance sensor 26 is not turned on within a predetermined time, jam processing is performed (s254, s255).

  If the reading entrance sensor 26 is ON within a predetermined time, the reading entrance sensor 26 is temporarily stopped at the nip portion between the reading entrance roller 8 and the driven roller 9 for back side reading (s256). In flow S <b> 16, the reading motor 103 stops driving when the leading edge of the document is detected by the reading inlet sensor 26 in order to perform skew correction by abutting the leading edge of the document against the nip portion of the reading inlet roller 8. After the leading edge of the document is detected, the feeding amount of the document corrected by the document length, the enlargement ratio, etc. is started (s257). When the count value of the conveyance amount reaches a predetermined amount, the feeding motor 102 is stopped ( At s259), the registration is stopped (s260).

After the resist stop in the flow S16, the process returns to return to the reading start of s223 in FIG. 6, and follows the yes route of the single-sided mode in the same manner as the front side reading. Then, the document whose registration is stopped for reading the back side is conveyed to the reading position at a conveyance speed corresponding to the designated magnification after receiving the reading start signal in the same manner as when reading the front side (s223) to (s252).

  When the reading of the back surface is completed, in order to align the front and back of the page, the scanned document is sent again in the B direction to perform the document reversal operation and pass over the glass 41. At the time of the reversing operation for page alignment, it is not necessary to carry the sheet at a speed corresponding to the reading magnification. When the trailing edge of the original passes under the paper discharge outlet sensor 29, the speed is reduced and the double-sided read original is discharged to the paper discharge tray 14, and the paper feed motor 102 and the read motor 103 are stopped (s264). The completion is transmitted to the main body control unit 111 (s265) (flow S15).

  Next, FIG. 8 shows an example of a drive circuit for the reversing solenoid 105, and FIGS. 9 to 11 show an example of a solenoid duty drive control routine. The CPU 50 in FIG. 8 is mounted on the controller 100, and the solenoid 51 is the same as the reverse solenoid 105. The CPU 50 outputs a pulse signal (PWM control signal) for energizing the solenoid to the solenoid drive circuit 52 according to a predetermined program. This pulse signal is output based on a timing pulse or a random number table incorporated in the CPU 50. This pulse signal sets a cycle so as not to resonate with the ADF device 200 main body, the switching claw 15 or the spring of the switching claw 15, and the gear meshing vibrations of the motors 101 to 104. This period control may be performed by controlling the pulse duration of the positive voltage or negative voltage of the pulse for a long time, or by controlling the length of the zero voltage of the pulse, or by adjusting the ratio of the positive voltage or the negative voltage to 0 volts. May be.

  FIG. 9A shows a main routine for controlling the reversing solenoid 51, and FIGS. 9B to 11D are executed based on the value of the job counter in the main routine of FIG. 9A. Indicates a subroutine to be executed. As shown in the main routine of FIG. 9A, in the case of solenoid duty driving, the CPU 50 calls a program for solenoid duty driving from a memory area (not shown) and starts control of the reverse solenoid 51.

The called solenoid duty drive program checks the job counter of the reverse solenoid 51 (s300). In this check, if the job counter is not 0, it is checked whether or not the reverse solenoid 51 is duty-driven (s301). If the duty drive control of the reverse solenoid 51 is performed (ON), the job counter is set to 0 ( s302) Return before starting the solenoid drive processing program.

Check the stiff ° s300, when it is no in decision inversion solenoid job counter ≠ 0, that is, reversing solenoid job counter is 0, or, reversing the solenoid 51 in stiff ° s301 is if Kere such is OFF, reversing solenoid job counter Is checked (Step s303). Since the job counter can take a numerical value from 0 to 12, in checking the step s303, it is determined which of the numerical values from 0 to 12 the job counter takes and a predetermined numerical value is processed.

  When the job counter is 0, the routine (d2_sol0) in FIG. 9B is executed. When the job counter is 1, the routine (d2_sol1) in FIG. 9C is executed. If the job counter is 2, the routine (d2_sol2) in FIG. 10A is executed. If the job counter is 3, the routine (d2_sol3) in FIG. 10B is executed. If the job counter is 4, the routine (d2_sol4) in FIG. 10C is executed. If the job counter is 5, the routine (d2_sol5) in FIG. 10D is executed. Similarly, a flag for processing until the value of the job counter reaches 12 is determined. In the process of FIG. 9A, if the reverse solenoid 51 is OFF, the reverse solenoid job counter is set to 0 (step s301) and the process returns.

FIG. 9B shows a routine (d2_sol0) when the job counter is 0. If the job counter is 0, it is checked whether or not the reverse solenoid 51 of the solenoid drive IC 52 composed of a Darlington transistor array or the like is duty-driven (reverse solenoid = ON) (s310). In this check, if the reverse solenoid 51 is not driven by duty (reverse solenoid = ON), the process returns to step s300 in FIG. 9A.

  If the reverse solenoid 51 is to be driven by a duty (reverse solenoid = ON), the interval timer is set to 0 (step s311), the reverse solenoid job counter is incremented by 1 (step s312), and the process returns.

  Since the reverse solenoid job counter is set to 1, the process proceeds from step s300 to step s301, and a check is made as to whether or not the reverse solenoid 51 is to be duty driven (performed = ON, not performed = OFF). When duty driving of the reversing solenoid 51 is performed (ON), the routine proceeds to step s303 and the routine (d2_sol1) of FIG. 9C is executed.

  FIG. 9C shows a routine (d2_sol1) when the job counter is 1. When the job counter is 1, it is checked whether the interval timer for which the reverse solenoid 51 is ON is 250 ms or more (step s313), and if the interval timer is less than 250 ms, the process returns. The interval timer starts counting when the reverse solenoid 51 is turned on. If the interval timer is 250 ms or longer, the reverse solenoid 51 is temporarily turned off to stop the duty drive (step s314), 1 is added to the reverse solenoid job counter (step s315), and the process returns.

In the routine (d2_sol1) of FIG. 9C, the suction state is continuously maintained for a predetermined time (250 ms in the present embodiment) after the plunger suction by the reversing solenoid 51 is started (s313). Further, thereafter, the energization to the reversing solenoid 51 is temporarily turned off (s314). As a result, the time required for driving the switching claw 15 is ensured and the time during which the vibration during load driving is sufficiently attenuated is ensured. The suction operation start timing of the reversing solenoid 51 is determined by detecting the document transport position by the paper discharge port sensor 29 arranged in the document transport path. At this time, the time required to drive the switching claw 15 as a load , i.e. taking into account the time until the suction operation of the reversing solenoid 51 is completed, the arrangement of the discharge outlet sensor 29 so as to changeover Introduction completion of the conveying path before the document passes through the position of the switching claw 15 Decide. After this step (s314), 1 is added to the reverse solenoid job counter (s315) and the process returns.

  Next, duty drive control for intermittently turning on / off the energization of the reversing solenoid 51 is started. At this time, the duty drive cycle is such that the suction force of the reversing solenoid 51 can maintain a sufficiently large value with respect to the return force by a spring (coil spring, string spring, etc.) set on the switching claw 15 side (for example, 1 kHz). Degree).

  In this embodiment, as shown in routine S18 (d2_sol2) in FIG. 10A, routine S19 (d2_sol3) in FIG. 10B, and routine S20 (d2_sol4) in FIG. The solenoid ON period for 3 rounds of the main routine is secured.

  FIG. 10A shows a routine (d2_sol2) when the job counter is 2. When the job counter is 2, the current required for driving the reversing solenoid 51 is supplied by the solenoid driving IC 52 to attract the plunger, and the reversing solenoid 51 temporarily turned off as described above is turned on (step s400). ). Thereafter, 1 is added to the reverse solenoid job counter (step s401) and the process returns. As a result, the processing returns to the processing of the job counter 3 (s300).

  FIG. 10B shows a routine (d2_sol3) when the job counter is 3. If the job counter is 3, 1 is added to the reverse solenoid job counter and the process returns (s402). As a result, the processing of the job counter 4 is started (s300).

  FIG. 10C shows a routine (d2_sol4) when the job counter is 4. If the job counter is 4, 1 is added to the reverse solenoid job counter and the process returns (s403). As a result, the processing of the job counter 5 is started.

  FIG. 10D shows a routine (d2_sol5) when the job counter is 5.

  Further, as shown in the routine (d2_sol5) in FIG. 10D, the added value of the reverse solenoid job counter is varied using the duty counter (s500 to s514).

  For example, when the duty counter = 0, the job counter addition value is set to 1 (s514), and the time shown in FIGS. 11A to 11D (four main routines, FIG. 10A) Solenoid ON time is set by including (D). Thereafter, the solenoid OFF period for three rounds of the main routine shown in FIGS. 11E to 11G is set. 10A to 10C again, and the determination of s512 is made based on the duty counter value (= 1) set last time in FIG. 10D.

If it is determined in s512 that the duty counter = 1, 2 is added to the job counter value and the process returns. Thus, the job counter = 7 flag (d2_sol7) in FIG. 11B is executed. In the job counter = 7 flag (d2_sol7), 1 is added to the job counter, the job counter is set to 8, and the process returns to s300. In this way , the operations up to job counter 7 (d2_sol7), job counter 8 (d2_sol8), and job counter 9 (d2_sol9) are performed. As a result, the reversing solenoid 51 is turned on for a period of three rounds of the main routine of FIG. 9 (a total of seven rounds including those of FIGS. 10A to 10D) .

  After the job counter 9 returns, the job counter 10 is processed by the job determination (s303). In the job counter 10 of the process (d2_sol10) in FIG. 11E, after turning the reverse solenoid 51 OFF, 1 is added to the job counter and the job counter 11 is returned (flow S22). In the job counter 11 (d2_sol11), the job counter is set to 12 with the reverse solenoid 51 turned off, and the process returns. In the process of the job counter 12 (d2_sol12), the job counter is set to 2 with the reverse solenoid 51 turned off, and the process returns. That is, the reversing solenoid 51 is turned OFF for the time of three main routines (duty driving continues).

  When the job counter becomes 2, the next solenoid ON period is reached, and again the solenoid ON time of FIGS. 10A to 10C is returned to the duty counter value (= 2) set last time in FIG. 10D. Based on the determination of S510, 3 is added to the job counter, and the solenoid of the main routine shown in FIGS. 11C and 11D for two laps (a total of six laps including FIGS. 10A to 10D). It becomes ON period.

  Similarly, the increment value of the job counter is incremented by 1 until the duty counter reaches 4, while 1 is added to the duty counter. When the duty counter becomes 4, the job counter of the reversing solenoid 51 becomes 10 in s507, and the reversing solenoid 51 becomes the ON time for four turns of FIG. 10 (A) to FIG. 10 (D), while FIG. ) To FIG. 11 (G), the time corresponding to three rounds is OFF.

  When the duty counter reaches 5 in s504, 4 is added to the job counter 5, while 6 is substituted into the duty counter (s505). Thus, after the return, the process of the job counter 9 (d2_sol9) to the process of the job counter 12 (d2_sol12) are performed.

  Since the main routine shown in FIGS. 9 to 11 is repeated until the duty counter reaches 7, the ON time and OFF time (time from the rising edge to the falling edge) of the reverse solenoid 51 are changed and adjusted.

  As described above, the solenoid ON period shown in FIGS. 11A to 11D is changed by changing the value added to the job counter value by the determination of the duty counter in the routine (d2_sol5). The frequency in the duty drive can be variably adjusted. Also, since FIGS. 10A to 10D always pass, the energization time to the solenoid during duty driving can be secured for at least four main routines, and the suction force of the reversing solenoid 51 is an external force (spring). A sufficiently large value can be taken with respect to the return force.

  FIG. 11 (H) shows a routine for changing with reference to the pseudo random number table value instead of the routine of FIG. 10 (D). In the case of FIG. 11H, the routine (d2_sol5 ') is performed. In this routine, the random number table reference value is substituted for the job counter value a, the value a is added to the reverse solenoid job counter, and the process returns.

  In FIG. 11I, a routine (d2_sol5 '') is performed that changes using the lower 3 bits of the transport length data instead of the routine of FIG. 10D. In this routine, the lower 3 bits of the transport length data are substituted into the reverse solenoid job counter value a for the job counter value a, the value a is added to the reverse solenoid job counter, and the process returns.

  The routine S22 shown in FIG. 11 (E) is changed to a method of changing by referring to a pseudo random number table value set in advance in the program as shown in the routine S23 of FIG. 11 (H). As shown in the routine S24, when changing to a method of changing by the random number data calculated based on the detection result of the conveyance length in the document conveyance operation, the fluctuation period is not uniquely determined, so the natural frequency and each frequency are not conscious. However, noise generation due to resonance can be suppressed.

  In the above embodiment, assuming that the time required for one round of the main routine is sufficiently short and stable with respect to the duty drive cycle, the duty solenoid drive counter is incremented while incrementing the reverse solenoid job counter every round of the main routine. Although the cycle setting is changed, the duty drive cycle may be generated using the timer interrupt function.

  In this embodiment, an example in which the ON period of the reversing solenoid 51 is varied is shown. However, if the period variation by the duty control counter shown in the routine S21 is also adopted in the solenoid OFF operation after the routine S22, the OFF time is set. It is also possible to vary it, and it is also possible to implement control to arbitrarily vary both the ON / OFF times.

  Further, the basis for determining the above-described duty drive cycle includes the following motor drive frequency in document conveyance, the gear meshing frequency constituting the document conveyance drive unit, the natural frequency of the spring for returning the switching claw 15, and the ADF device In consideration of not matching the frequency such as the natural frequency of 200, the problem of noise generation due to resonance with the chopping sound by duty driving can be avoided.

  As described above, according to the ADF apparatus 200 according to this embodiment, the controller 100 starts the duty drive control of the reversing solenoid 105 based on the information detected by the sensors 20 to 30. The energization start timing is optimized. For this reason, the heat generation of the coil of the reversing solenoid 105 is suppressed, and a temperature rise of the reversing solenoid 105 can be suppressed and a cost increase can be prevented without requiring a special configuration for preventing heat generation. Since the duty driving control of the reversing solenoid 105 is performed after detecting the original which is the conveyed paper sheet, the driving time is short, the chopping driving sound of the solenoid can be reduced, and the power is saved.

Further, as shown in the flow charts of FIGS. 9 to 11, by changing the drive period (ratio between the chopping ON period and the chopping OFF period) of the inverting solenoid 105, the beat sound generated during the chopping drive is changed. By spreading the frequency, resonance with the apparatus main body can be avoided, and noise can be reduced. In addition, since the drive cycle of duty drive is changed every cycle, even when the solenoid energization time is short, resonance with the frequency of other devices such as the device main body and motor can be avoided by reducing the drive frequency, and noise reduction An effect can be obtained. Further, resonance between the motors 101 to 104 and the reversing solenoid 105 and resonance with the spring driving the switching claw 15 such as a gear driving the roller can be prevented, and noise due to resonance with the spring can be reduced. Further, an increase in noise due to resonance with the natural frequency of the entire ADF device 200 can be prevented.

  As shown in FIG. 11H, the controller 100, which is an energization control means, uses a random number for the fluctuation amount rate at which the drive cycle fluctuates when performing duty driving. The generation of noise can be prevented without being aware of the resonance. When determining the fluctuation rate of this driving cycle with a random number, this random number is determined based on the detection result of the paper sheet, so that the periodic fluctuation rate of the solenoid can be determined randomly according to the conveyance length of the paper sheet, The noise generation probability of the solenoid can be lowered and the time can be shortened even if noise is generated.

Also, if only the period of chopping ON (positive voltage application) is varied in one cycle of duty driving, the attractive force can be maintained at a certain level or higher. Further, when varying only the drive period can be stabilized duty driving in one cycle. Further, if only the period of chopping OFF (0 level) is changed in one cycle of duty driving, the attractive force during the ON period can be stabilized.

FIG. 1 is a diagram showing a schematic configuration of an ADF apparatus as a paper sheet conveying apparatus according to an embodiment of the present invention. FIG. 2 is a block circuit diagram of a controller that controls the ADF apparatus according to the embodiment, and elements and devices connected to the controller. FIG. 3 is a flowchart showing processing steps of the ADF apparatus according to the embodiment. The flowchart which shows the continuation process process of the process process of the ADF apparatus of FIG. FIG. 5 is a flowchart of reading execution of the ADF apparatus according to the embodiment. 6 is a flowchart showing the continuation of the reading execution process of FIG. FIG. 7 is a flowchart showing the continuation of the reading execution process of FIG. FIG. 8 is a circuit diagram showing a connection state between a CPU of a controller and a solenoid drive circuit in the ADF apparatus. (A) is a flowchart of a main routine showing processing of reverse solenoid control, (B) is a flowchart of a subroutine d2_sol0 when the job counter is 0, and (C) is a flowchart of a subroutine d2_sol1 when the job counter is 1. (A) is a flowchart of the subroutine d2_sol2 when the job counter is 2, (B) is a flowchart of the subroutine d2_sol3 when the job counter is 3, (C) is a flowchart of the subroutine d2_sol4 when the job counter is 4, (D ) Is a flowchart of the subroutine d2_sol5 when the job counter is 5. (A) is a flowchart of the subroutine d2_sol6 when the job counter is 6, (B) is a flowchart of the subroutine d2_sol7 when the job counter is 7, (C) is a flowchart of the subroutine d2_sol8 when the job counter is 8, (D ) Is a flowchart of the subroutine d2_sol9 when the job counter is 9. (E) is a flowchart of the subroutine d2_sol10 when the job counter is 10, (F) is a flowchart of the subroutine d2_sol11 when the job counter is 11, (G) is a flowchart of the subroutine d2_sol12 when the job counter is 12, (H) ) Is a flowchart of a subroutine d2_sol5 ′ showing a process when a random number reference value is substituted into the job counter, and (I) is a subroutine d2_sol5 ″ showing a process when the lower 3 bits of the conveyance length data are substituted into the job counter as a random value. Flow chart.

Explanation of symbols

DESCRIPTION OF SYMBOLS 0 Document bundle 1 Document table 2 Stop claw 3 Pickup roller 4 Reverse roller 5 Paper feed belt 6 Pull-out roller 7 Driven roller 8 Reading entrance roller 9 Driven roller 10 Reading exit roller 11 Driven roller 12 Paper discharge roller 13 Lower driven roller 14 Paper discharge Tray 15 Switching claw 16 Reverse roller 17 Driven roller 18 Upper driven roller 19 Document set sensor 20-22 Document length sensor 23 Separation sensor 24 Abutment sensor 25 Document width sensor 26 Reading entrance sensor 27 Registration sensor 28 Document sensor 29 Paper discharge port sensor 30 Reading Exit Sensor 31 Document Set Filler 33 Pickup Home Position Sensor 34 Nail Home Position Sensor 40 Guide Plate 41 Glass 50 CPU
51 Reverse solenoid 52 Solenoid IC (drive circuit)
DESCRIPTION OF SYMBOLS 100 Controller 101 Calling motor 102 Paper feed motor 103 Reading motor 104 Reverse motor 105 Reverse solenoid 106 Finished stamp 107 Interface 111 Main body control part 200 ADF apparatus (paper sheet conveyance apparatus)

Claims (9)

A plurality of transport paths for transporting the paper sheet, path switching means for switching the transport destination of the paper sheet relative to the transport path, and a solenoid for performing a switching operation of the path switching means, The solenoid includes a movable iron core that performs the switching operation of the path switching means, a spring that positions the movable iron core at a predetermined position, and a coil that drives the movable iron core against the elastic force of the spring. A conveying device,
Energization control means for duty-driving the coil with a pulse current within a range in which the force for guiding the movable iron core does not decrease with respect to the elastic force of the spring, and the paper sheet conveyed in the conveyance path is detected. A sheet detection unit, and the energization control unit starts duty drive control of the coil based on information detected by the sheet detection unit and detects the duty drive chopping. A paper sheet conveying apparatus characterized in that the ratio between the ON period and the chopping OFF period is changed every cycle . A method for driving the paper sheet conveying apparatus according to claim 1,
The energization control means varies the ratio of the chopping ON period and the chopping OFF period so as to be different from the driving frequency of a motor used for conveying the paper sheet. . In the driving method of the paper sheet conveying apparatus according to claim 1 ,
The energization control means varies the ratio of the chopping ON period and the chopping OFF period so as to be different from the meshing frequency of the driving gear of the driving means for conveying the paper sheet. Driving method of the transport device. In the driving method of the paper sheet conveying apparatus according to claim 1 ,
The sheet feeding apparatus driving method according to claim 1, wherein the energization control means varies the ratio of the chopping ON period and the chopping OFF period so as to be different from the natural frequency of the spring of the path switching means . In the driving method of the paper sheet conveying apparatus according to claim 1 ,
The sheet feeding apparatus driving method according to claim 1, wherein the energization control means varies the ratio of the chopping ON period and the chopping OFF period so as to be different from the natural frequency of the entire path switching means . In the driving method of the paper sheet conveying apparatus according to claim 1 ,
The energization control unit varies the ratio of the chopping ON period and the chopping OFF period using a random number table, and the driving method of the paper sheet conveying apparatus, In the driving method of the paper sheet conveying apparatus according to claim 1 ,
The energization control unit varies a ratio between the chopping ON period and the chopping OFF period using random number data set based on the detection result of the sheet conveyance length . Driving method. In the driving method of the paper sheet conveying apparatus according to claim 1 ,
The energization control means varies the ratio of the chopping ON period and the chopping OFF period by varying only the chopping ON period within one cycle of the duty driving, and driving the paper sheet conveying apparatus Method. In the driving method of the paper sheet conveying apparatus according to claim 1 ,
The energization control means varies the ratio of the chopping ON period and the chopping OFF period by varying only the chopping OFF period within one cycle of the duty driving, and driving the paper sheet conveying apparatus Method.