JP5563540B2 - Automatic document feeder and image reading apparatus - Google Patents

Description

  The present invention relates to an automatic document conveying device and an image reading device that are used in a copying machine, a printer, and the like and automatically convey a document to read a document image.

  In an image reading apparatus including an automatic document feeder and an image reading unit such as a scanner used in an image forming apparatus such as a copying machine or a printer, an increase in image reading speed is required. As an image reading apparatus that increases the reading speed of an original image, the image reading unit has a first conveyance path for conveying an original to an image reading unit and a second conveyance path different from the first conveyance path. An image reading apparatus that conveys an original by alternately distributing the original to the first and second conveyance paths when reading an image is known as a conventional technique.

JP 2009-253984 A

  However, according to the prior art, a document jam (jamming) occurs in the middle of reading an image by continuously conveying a document (particularly, a document whose length in the transport direction is equal to or shorter than the length of the first and second transport paths). When the original remains in each of the first and second transport paths, it is not possible to distinguish between the preceding document and the subsequent document, and the original is removed from the first and second transport paths, and then returned to the paper feeding unit. It was difficult to set the originals in the correct order (jam processing).

  SUMMARY OF THE INVENTION The present invention solves the above-described problem. When an original is continuously conveyed and an image is read, the original is conveyed to the image reading unit using a first conveyance path and a second conveyance path different from the first conveyance path. The original image is read efficiently by conveying at high speed, and even if a jam occurs and the original remains in each of the first and second conveyance paths, the preceding original and the subsequent original are distinguished. It is an object of the present invention to provide an automatic document feeder and an image reading device that can convey a document so that the jamming process can be facilitated.

  In order to solve the above-described problems, the present invention provides a paper feeding unit that feeds originals whose images are read by the image reading unit one by one, and a document fed by the paper feeding unit. The first conveyance unit that conveys the document in the direction of the image reading unit and the document fed by the sheet feeding unit via the second conveyance path different from the first conveyance path, the image A third conveyance unit that conveys the original conveyed by the second conveyance unit that conveys in the direction of the reading unit and the first conveyance unit and the second conveyance unit alternately one by one to the image reading unit. A conveyance unit, a determination unit that determines that a document is held between the third conveyance unit, and a document that is fed by the sheet feeding unit are alternately placed on the first conveyance path and the second conveyance path. If there is a preceding document that is sorted and sent, is the preceding document determined by the determination unit? The document of the trailing, characterized by comprising a document sorting conveyor unit for feeding the conveying path where the document is not fed in the preceding of said first and second conveying paths.

1 is a configuration diagram schematically showing an automatic document feeder and an image reading apparatus according to an embodiment of the present invention. 2 is a block diagram showing a control system of the automatic document feeder according to the embodiment. FIG. 6 is a flowchart illustrating processing from power-on to document feed start according to the embodiment. 6 is a flowchart illustrating processing from feeding a document according to the embodiment to transporting the document to a first transport path. 6 is a flowchart illustrating document conveyance processing using the first conveyance path according to the embodiment. 6 is a flowchart illustrating processing from the start of image reading to the end of reading according to the embodiment. 6 is a flowchart illustrating a subsequent document conveyance process using the second conveyance path according to the embodiment. It is a flowchart which shows completion of the conveyance process of embodiment. FIG. 6 is an explanatory diagram illustrating a state at the start of feeding of the first document according to the embodiment. FIG. 10 is an explanatory diagram illustrating a state when the first original document is transported to the first transport path according to the embodiment. FIG. 6 is an explanatory diagram illustrating a standby state of a first document in the first conveyance path according to the embodiment. FIG. 6 is an explanatory diagram illustrating a state at the start of feeding of a second document according to the embodiment. FIG. 10 is an explanatory diagram illustrating a state when the second original document is conveyed to a second conveyance path according to the embodiment. FIG. 6 is an explanatory diagram illustrating a conveyance state of a second document following the first document according to the embodiment. 4 is an explanatory diagram illustrating a distance between a first document and a second document according to the embodiment. FIG. FIG. 5 is an explanatory diagram illustrating a state at the start of feeding of a third document according to the embodiment. FIG. 10 is an explanatory diagram illustrating a state when a third original document is conveyed to a first conveyance path according to the embodiment.

  Hereinafter, an automatic document feeder and an image reading apparatus according to an embodiment will be described with reference to the accompanying drawings.

  FIG. 1 shows an image reading apparatus 100 according to an embodiment. The image reading apparatus 100 includes a scanner 110 that is a first image reading unit and an automatic document feeder (ADF) 10 that transports a document G to the scanner 110. The scanner 110 includes a READ document glass 110a, a platen glass 110b serving as a document placement table, and an optical mechanism 110c. The optical mechanism 110c optically reads an image of the document G running on the READ document glass 110a. Alternatively, the optical mechanism 110c is moved in the direction of arrow A (see FIG. 1) by a driving unit (not shown) along the platen glass 110b, and optically reads an image of the document G placed on the platen glass 110b. The scanner 110 includes a CCD (Charge Coupled Device) 110d that photoelectrically converts an optical signal from the optical mechanism 110c into an electrical signal.

  The automatic document feeder 10 is attached to the scanner 110 so as to be openable and closable by a hinge portion (not shown). When the automatic document feeder 10 is open, the READ document glass 110a and the platen glass 110b are exposed, and in the closed state (the state shown in FIG. 1) The original glass 110a and the platen glass 110b are covered, and the original G is continuously conveyed to the READ original glass 110a.

  The automatic document feeder 10 feeds the document G, whose image is read by the scanner 110, one by one, and feeds the document G fed by the paper feeder through the first transport path. The first conveyance unit that conveys the scanner 110 in the direction of the READ original glass 110a, and the original G that is fed by the paper feeding unit passes through a second conveyance path that is different from the first conveyance path. READ document glass 110a of the scanner 110 is sandwiched alternately one by one by a second transport unit that transports in the direction of the document glass 110a, the document G transported by the first transport unit and the second transport unit. And a document sorting and feeding unit that alternately feeds the document G fed by the feeding unit to the first and second feeding paths.

  The paper feeding unit includes a document tray 11 on which the documents G are stacked, a pickup roller 12 that picks up the document G from the document tray 11, and a document G in order to prevent the document G from being overlapped (double feed). It has a separation roller 13 (consisting of a pair of rollers) that separates and conveys the sheets one by one.

  The first conveyance unit serves as the first conveyance path, an OUT conveyance path 16 reaching a READ document glass 110a from a registration roller 14 (comprising a pair of rollers) described later, and an OUT conveyance path as a first intermediate conveyance roller. 16 has an intermediate OUT roller 18 (consisting of a pair of rollers) provided in the middle of the line 16.

  The second transport unit is provided in the middle of the IN transport path 17 as the second transport path, as an IN transport path 17 reaching a READ document glass 110a from a registration roller 14 described later, and as a second intermediate transport roller. It has an intermediate IN roller 28 (consisting of a pair of rollers).

  The third transport unit includes a pre-reading roller 50 (comprising a pair of rollers) that transports the document G that has passed through the OUT transport path 16 or the IN transport path 17 to the READ document glass 110a of the scanner 110. The conveyance path length of the OUT conveyance path 16 (distance from the registration roller 14 via the OUT conveyance path 16 to the pre-reading roller 50) and the conveyance path length of the IN conveyance path 17 (from the registration roller 14 to the IN conveyance path 17) The distance to the pre-reading roller 50 via) has, for example, a letter-size paper length (216 mm) that is most often used. Accordingly, when a document having a size smaller than the letter size is transported, the document G is configured to be accommodated in the OUT transport path 16 and the IN transport path 17 during the transport.

  The document sorting / conveying section is provided on the downstream side of the separation roller 13, and a registration roller 14 that aligns the leading edge of the document and a gate that sorts the document G conveyed by the registration roller 14 to the OUT conveyance path 16 or the IN conveyance path 17. 40.

  The automatic document feeder 10 further includes a post-reading roller 51 (comprising a pair of rollers) for discharging the document G from the READ document glass 110a, a pre-discharge roller 52 (comprising a pair of rollers), and a discharge roller 53 (comprising a pair of rollers). And a paper discharge tray 56. The post-reading roller 51, the pre-discharge roller 52, and the discharge roller 53 constitute a discharge unit. Between the post-reading roller 51 and the pre-discharge roller 52, a contact image sensor (CIS) 60, which is a second image reading unit, is provided. The contact image sensor (CIS) 60 may be provided in a conveyance path from the pre-discharge roller 52 to the discharge roller 53, for example.

  The scanner 110 reads an image of the surface, which is the first surface of the document G running on the glass surface, with the READ document glass 110a. The CIS 60 reads an image on the back surface, which is the second surface of the traveling original G. Thereby, the images on both sides of the original G can be read by one original conveyance.

  An empty sensor 70 that detects the presence or absence of the document G is disposed on the document tray 11, and a registration sensor 71 that detects that the document G has reached the registration roller 14 is disposed between the separation roller 13 and the registration roller 14. To do.

  A paper timing sensor OUT72, which is a first timing sensor that detects the driving timing of the registration roller 14 and the intermediate OUT roller 18, is disposed in the OUT conveyance path 16. A paper timing sensor IN73, which is a second timing sensor for detecting the driving timing of the registration roller 14 and the intermediate IN roller 28, is disposed in the IN conveyance path 17. Further, an ADF opening / closing detection sensor 90 for detecting opening / closing of the automatic document feeder 10 is disposed on the upper portion of the scanner 110.

  A pre-reading sensor 76 is arranged between the pre-reading roller 50 and the READ original glass 110 a, and a reading sensor 77 is arranged between the post-reading roller 51 and the CIS 60. A paper discharge sensor 78 is disposed while the paper discharge roller 52 reaches the paper discharge roller 53.

  For example, the empty sensor 70 is turned on when there is a document G and turned off when there is no document, thereby detecting the presence or absence of the document G. The sensors 71, 72, 73, 76, and 78 detect the document G by turning on when the document G reaches the sensor position and turning off when the document G passes the sensor position. The ADF opening / closing detection sensor 90 detects opening / closing of the ADF 10 by turning off when the ADF 10 is in the open state and turning on when the ADF 10 is in the closed state.

  When the sheet feeding motor 80 is turned on, the pickup roller 12 and the separation roller 13 are driven to rotate. When the sheet feeding motor 80 is turned off, the driving rotation of the pickup roller 12 and the separation roller 13 is stopped. The pickup solenoid 81 is turned on / off to swing the pickup roller 12. When the registration motor (registration motor) 82 is turned on, the registration roller 14 is driven to rotate. When the registration motor 82 is turned off, the driving rotation of the registration roller 14 is stopped.

The gate solenoid 83 switches the gate 40. When the gate solenoid 83 is turned off, the gate 40 rotates in the direction of the arrow x, and distributes the document G to the OUT conveyance path 16 that is the first conveyance path. When the gate solenoid 83 is turned on, the gate 40 rotates in the direction of the arrow y, and distributes the document G to the IN conveyance path 17 that is the second conveyance path.

  The intermediate OUT motor 84 drives and rotates the intermediate OUT roller 18 when turned on, and stops driving and rotating the intermediate OUT roller 18 when turned off. The intermediate IN motor 86 drives and rotates the intermediate IN roller 28 when turned on, and stops driving and rotating the intermediate IN roller 28 when turned off. The READ motor 87 drives and rotates the pre-reading roller 50, the post-reading roller 51, and the pre-discharge roller 52 when turned on, and stops driving rotation of the pre-reading roller 50, the post-reading roller 51, and the pre-discharge roller 52 when turned off. . When the paper discharge motor 88 is turned on, the paper discharge roller 53 is driven to rotate. When the paper discharge motor 88 is turned off, the drive rotation of the paper discharge roller 53 is stopped.

  FIG. 2 shows a block diagram of a control system 120 mainly composed of the ADF 10. A main body control unit 121 that controls the entire image forming apparatus including the image reading apparatus 100 is connected to the CCD 110 d and the CIS 60 of the scanner 110. The main body control unit 121 controls the CPU 130 of the ADF 10 via the input / output interface 122. An empty sensor 70, a registration sensor 71, a paper timing sensor OUT72, a paper timing sensor IN73, a pre-reading sensor 76, a reading sensor 77, a paper discharge sensor 78, and an ADF open / close detection sensor 90 are connected to the input side of the CPU 130.

  A pickup solenoid 81, a paper feed motor 80, a registration motor 82, a gate solenoid 83, an intermediate OUT motor 84, an intermediate IN motor 86, a READ motor 87, and a paper discharge motor 88 are connected to the output side of the CPU 130. The CPU 130 has a timer function inside, and controls the motor and the solenoid based on the timer measurement result and the sensor detection result, and together with the main body control unit 121, controls the document and reads the document image. Execute.

  With the above-described configuration, the gate 40 and the registration roller 14 cooperate to alternately distribute and send the document G that is continuously conveyed to the OUT conveyance path 16 and the IN conveyance path 17. At this time, the registration roller 14 is rotated so that the preceding document G is clamped by the pre-reading roller 50, that is, when the pre-reading sensor 76 is turned on, the registration roller 14 rotates and moves the succeeding document G to the OUT conveyance path 16 and The preceding document G in the IN conveyance path 17 is sent to the conveyance path where it has not been sent.

  Accordingly, when a jam occurs during the continuous conveyance of the original G of the letter size or smaller, the preceding original G and the subsequent original G exist in the respective conveyance paths of the OUT conveyance path 16 and the IN conveyance path 17. In some cases, the preceding document G is always held by the pre-reading roller 50. For this reason, even when the jam of the original G occurs and the original G remaining on the OUT conveyance path 16 and the IN conveyance path 17 is removed, which original G is the preceding original G or the subsequent original G. It is possible to easily determine whether there is a jam, and jam processing is facilitated.

  The intermediate IN roller 28 and the intermediate OUT roller 18 are arranged so that the trailing edge of the preceding document G on one of the OUT conveyance path 16 and the IN conveyance path 17 and the succeeding document G on the other conveyance path The document G is continuously and efficiently conveyed to the scanner 110 in a state where the distance from the front end is approximately 0 mm. Therefore, the scanner that operates according to the control process of the main body control unit 121 can read the image of the document G at high speed.

  Next, a control process for continuously conveying the original G and reading an image will be described in detail with reference to flowcharts shown in FIGS. First, a control process for conveying the first original G1 will be described. When a power supply (not shown) of the main unit is turned on, the CPU 130 waits for the ADF opening / closing sensor 90 to be turned on in ACT 200 of FIG. When the ADF opening / closing sensor 90 detects the closed state of the ADF 10 and is turned on, the CPU 130 confirms that the ADF 10 is closed based on the ADF opening / closing sensor 90 being on.

  Next, in ACT 201 in FIG. 3, the CPU 130 confirms whether all the sensors 71, 72, 73, 76, 77, 78 in the transport path are off. The CPU 130 confirms that all the sensors 71, 72, 73, 76, 77, 78 in the conveyance path are off, and determines that the document G does not exist in all the conveyance paths of the ADF 10.

  Next, in ACT 202 of FIG. 3, the CPU 130 waits for the empty sensor 70 to be turned on. When the document G1 is placed on the document tray 11 by the user, the empty sensor 70 detects the document G1 and is turned on. The CPU 130 transmits a document on signal to the main body control unit 121 based on the empty sensor 70 being on. Thereafter, in ACT 203, the CPU 130 waits to receive a paper feed request signal from the main body control unit 121.

  In ACT 201, when the CPU 130 confirms that any one of the sensors is turned on, the CPU 130 determines that the document G1 exists in the conveyance path, and uses a display unit (not shown) or the like. Notifies that a document jam (jam) has occurred.

  When the CPU 130 receives a paper feed request signal from the main body control unit 121 in ACT 203 in FIG. 3, in ACT 206 in FIG. 4, the CPU 130 turns on the pickup solenoid 81 and turns on the paper feed motor 80. When the pickup solenoid 81 is turned on, the pickup roller 12 descends and comes into contact with the original G1 on the tray 11. When the paper feed motor is turned on, the pickup roller 12 rotates and starts feeding the original G1 from the tray. Further, when the paper feed motor 80 is turned on, the separation roller 13 is rotated and the paper G1 fed from the tray 11 is conveyed. Thereby, the feeding operation of the document G1 is started.

  Next, in ACT 207 of FIG. 4, the CPU 130 waits for the registration sensor 71 to be turned on. When the registration sensor 71 detects the document G1 and is turned on, in ACT 208, the CPU 130 turns off the paper feed motor 80 and turns off the gate solenoid 83 after a certain period of time after the registration sensor 71 is turned on.

  The original G1 is conveyed for a certain period of time by the rotation of the pickup roller 12 and the separation roller 13, then hits the registration roller 14, and as shown in FIG. When the gate solenoid 83 is turned off, the gate 40 is set in a direction in which the document G is distributed to the OUT conveyance path 16.

  If the registration sensor 71 does not turn on even after a predetermined time has elapsed in ACT 210 of FIG. 4, the CPU 130 determines that the document G has jammed and uses a display means (not shown) to generate a jam. Inform.

  Next, in ACT 211 in FIG. 4, the CPU 130 waits for a predetermined time to elapse. When the predetermined time has elapsed, in ACT 212, the CPU 130 determines whether or not the document G1 is an odd number. In this case, since the original G1 is the first one, the CPU 130 determines that it is an odd number. If it is determined that the original G1 is an odd number, the CPU 130 confirms whether or not the pre-reading sensor 76 is turned on by the preceding original G in ACT 265, and if the pre-reading sensor 76 is turned on, Proceed to ACT 214.

  However, when the document G1 is the first document (the preceding document G does not exist), the ACT 265 of FIG. In ACT 214, the CPU 130 turns on the registration motor 82 and the intermediate OUT motor 84 to rotate the registration roller 14 and the intermediate OUT roller 18 at a constant speed. As shown in FIG. 10, the original G1 is distributed to the gate 40 and proceeds to the OUT conveyance path 16.

  In ACT 215 and ACT 217 in FIG. 5, the CPU 130 waits for a certain time until the paper timing sensor OUT 72 is turned on. When the paper timing sensor OUT72 is turned on, in ACT 216, the CPU 130 turns off the registration motor 82 and the intermediate OUT motor 84 after a predetermined time from the turning on of the paper timing sensor OUT72 to stop the rotation. As shown in FIG. 11, the document G <b> 1 stops before the pre-reading roller 50.

  In the case of ACT 215 and ACT 217 in FIG. 5, if the paper timing sensor OUT 72 does not turn on even after a predetermined time has elapsed, the CPU 130 determines that a jam of the original G has occurred, and uses display means (not shown) or the like. Notify the occurrence of jam.

  In ACT 218 in FIG. 5, the CPU 130 waits for reception of a transport request signal from the main body control unit 121. When the conveyance request signal is received from the main body control unit 121, in ACT 220, the CPU 130 waits for a predetermined time to elapse after the leading edge of the preceding document G turns on the sensor 76 before reading. However, if the document G1 is the first document (the preceding document G does not exist), the ACT 220 is bypassed and the process proceeds to the ACT 221.

  In ACT 221 of FIG. 5, the CPU 130 turns on the intermediate OUT motor 84 and the READ motor 87, and at a speed according to the instruction of the main body control unit 121, the intermediate OUT roller 18, the pre-reading roller 50, the post-reading roller 51, The pre-discharge roller 52 is rotated.

  In ACT 230 of FIG. 6, the CPU 130 waits for a certain period of time. During this time, the intermediate OUT motor 84 and the READ motor 87 are kept on for a certain period of time, and at a speed in accordance with an instruction from the main body control unit 121, the intermediate OUT roller 18, the pre-reading roller 50, the post-reading roller 51, and the pre-discharge roller Continue to rotate 52 for a certain time. By continuing to rotate the intermediate OUT roller 18, the pre-reading roller 50, the post-reading roller 51, and the pre-discharge roller 52 for a predetermined time, the original G is conveyed by a predetermined distance. The CPU 130 turns on the intermediate OUT motor 84 and the READ motor 87 for a predetermined time, and then transmits a reading start signal to the main body control unit 121 in ACT 231 of FIG. The main body control unit 121 receives the reading start signal and starts reading the image on the surface of the document G1.

  As shown in FIG. 12, the document G1 travels on the READ document glass 110a. The scanner 110 performs image reading on the surface of the document G1. The original G1 travels on the READ original glass 110a, and then is conveyed in the direction of the paper discharge roller 53 through the post-reading roller 51 and the pre-discharge roller 52.

  In ACT 232 of FIG. 6, the CPU 130 waits for the paper discharge sensor 78 to be turned on. Thereafter, when the leading edge of the original G1 reaches the paper discharge sensor 78, the paper discharge sensor 78 detects the original G1 and is turned on. When the paper discharge sensor 78 is turned on, in ACT 233, the CPU 130 turns on the paper discharge motor 88 to rotate the paper discharge roller 53.

  In the case of double-sided reading, in ACT 237 of FIG. After the paper discharge sensor 78 is turned on, the main body control unit 121 waits for a certain period of time in ACT 238. After a predetermined time has elapsed, in ACT 241, the main body control unit 121 ends the image reading of the surface of the document G 1 by the scanner 110.

  When the trailing edge of the original G1 passes through the post-reading roller 51 and the reading sensor 77 is turned off, the CPU 130 turns off the READ motor 87 and the intermediate OUT motor 84 in ACT242 in FIG. Further, after a predetermined time has elapsed after the reading sensor 77 is turned off, the main body control unit 121 ends the image reading of the back side of the document G1 by the CIS 60.

  After that, in ACT 260 of FIG. 8, the CPU 130 determines whether the original G1 is the final original (for example, whether the empty sensor 70 is turned off after the original G1 is fed), and the original G1 is the final original. The CPU 130 executes a final document discharge operation. That is, the CPU 130 performs an operation of turning off all the motors and solenoids and ending the document image reading and conveying control process.

  Specifically, in ACT 261 in FIG. 8, the CPU 130 waits for the paper discharge sensor 78 to be turned off. After the paper discharge sensor 78 is turned off, in ACT 262, the CPU 130 continues to turn on the paper discharge motor 88 for a predetermined time and conveys the original G1 by a predetermined distance. When the document discharge motor 88 is kept on for a certain period of time and the document G1 is conveyed by a certain distance, in ACT 263, the CPU 130 turns off all the motors and solenoids. Thereby, the control process for conveying the original G1 and reading the image is completed.

  If the CPU 130 determines in ACT 260 of FIG. 8 that the document G1 is not the final document, the document is transported by the OUT transport path 16 and the IN transport path 17 without performing the paper discharge operation described below. Repeat as above.

  That is, the CPU 130 first turns on the registration sensor 71 in the ACT 207 in FIG. 4 with the first original G1, and the CPU 130 interrupts the second original separately from the control process for the first original G1. The feeding of the original G2 is started in parallel. However, the second original G2 waits for the paper feeding process until the trailing edge of the first original G1 passes through the registration sensor 71. In ACT 300 and ACT 301 of FIG. 4, the CPU 130 waits for the registration sensor 71 to be turned off when the trailing edge of the preceding first document G1 passes the registration sensor 71.

  When the registration sensor 71 is turned off in ACT 300 of FIG. 4, the CPU 130 turns on the pickup solenoid 81 and the paper feed motor 80 in ACT 206. When the pickup solenoid 81 is turned on, the pickup roller 12 descends and comes into contact with the document G2 on the tray 11. When the paper feed motor is turned on, the pickup roller 12 rotates, and as shown in FIG. 12, paper feed from the tray of the second original G2 is started. Further, when the paper feed motor 80 is turned on, the separation roller 13 is rotated, and the original G2 fed from the tray 11 is conveyed.

  When the leading edge of the document G2 reaches the position of the registration sensor 71, the registration sensor 71 detects the document G2 and is turned on in ACT 207 of FIG. When the registration sensor 71 is turned on, in ACT 208, the CPU 130 turns off the pickup solenoid 81 and the paper feed motor 80 after a predetermined time has elapsed since the registration sensor 71 was turned on. The original G2 comes into contact with the registration roller 14 and stops, and the leading edge thereof is aligned. In ACT 208, the CPU 130 turns off the gate solenoid 83 when the paper feed motor 80 is turned off.

  Next, in ACT 211 in FIG. 4, the CPU 130 waits for a certain period of time after the gate solenoid 83 is turned off. After a predetermined time has elapsed, in ACT 212, the CPU 130 determines whether the document G is an odd-numbered document or an even-numbered document. In this case, since it is the even-numbered (second) original G2, the CPU 130 turns on the gate solenoid 83 in ACT 250 of FIG. When the gate solenoid 83 is turned on, the gate 40 is switched to the direction in which the document G2 is distributed to the IN conveyance path 17.

  Next, in ACT 264 of FIG. 7, the CPU 130 holds the preceding first document G1 between the pre-reading rollers, the leading edge of the document G1 reaches the position of the pre-reading sensor 76, and the pre-reading sensor 76 is turned on. If the pre-reading sensor 76 is on, the process proceeds to ACT 251. When the pre-reading sensor 76 is turned on, in ACT 251, the CPU 130 turns on the registration motor 82 and the intermediate IN motor 86 to rotate the registration roller 14 and the intermediate IN roller 28 at a constant speed. When the registration motor 82 and the intermediate IN motor 86 are turned on, the second original G2 is distributed to the gate 40 and proceeds to the IN conveyance path 17 as shown in FIG.

  That is, the original G2 stands by until the preceding original G1 is sandwiched between the pre-reading rollers. Thereafter, the original G2 is conveyed to the IN conveyance path 17 by the registration roller 14 and the intermediate IN roller 28 in anticipation of the preceding original G1 being sandwiched between the pre-reading rollers.

  Next, in ACT 252 and ACT 254 of FIG. 7, the CPU 130 waits for the paper timing sensor IN73 to turn on. When the leading edge of the second original G2 reaches the position of the paper timing sensor IN73, the paper timing sensor IN73 is turned on. When the paper timing sensor IN73 is turned on, in ACT253, the CPU 130 turns off the registration motor 82 and the intermediate IN motor 86 after a predetermined time from the paper timing sensor IN73 being turned on. The second original G2 stops in front of the pre-reading roller 50 in the IN conveyance path 17.

  Thereafter, in ACT 256 of FIG. 7, the CPU 130 waits for reception of a conveyance request signal for the second original G <b> 2 from the main body control unit 121. If the paper timing sensor IN73 does not turn on after a predetermined time in the ACT 254, the CPU 130 determines that the document G1 is jammed as described above, and the jamming is performed by a display unit (not shown). Announce the occurrence.

    Next, in ACT 257 in FIG. 7, the CPU 130 waits for a predetermined time after the pre-reading sensor 76 is turned on by the preceding document G1 (first document G1). When the predetermined time has elapsed, in ACT 258, the CPU 130 turns on the intermediate IN motor 86 and the READ motor 87, and at a speed according to the instruction of the main body control unit 121, the intermediate IN roller 28, the pre-reading roller 50, and the post-reading roller 51 and the pre-discharge roller 52 are rotated.

  As a result, the CPU 130 starts conveying the leading edge of the preceding document G1 (first document G1) through the pre-reading roller 50 and the leading edge of the second document G2 by the pre-reading roller 50. Match timing. As shown in FIG. 14, in the state where the distance between the trailing edge α1 of the preceding document G1 (first document G1) and the leading edge β1 of the second document G2 is close to 0 mm, the second document G2 is Then, it is conveyed to the READ original glass 110a.

  In order to make the distance between the trailing edge α1 of the preceding document G1 (first document G1) and the leading edge β1 of the second document G2 close to 0 mm, the distance from the paper timing sensor OUT72 to the pre-reading roller 50 is set. The distance and the distance from the paper timing sensor IN73 to the pre-reading roller 50 are set to be equal.

  As shown in FIG. 15, after the paper timing sensor IN73 is turned on, the second original G2 stands by at a position advanced by a predetermined distance γ1. When the trailing edge of the preceding document G1 (the first document G1) passes through the paper timing sensor OUT72 and advances a certain distance γ1, the READ motor 87 and the intermediate IN motor 86 are turned on, and the second document G2 is read. It is conveyed in the direction of the READ original glass 110a. As a result, the distance between the trailing edge of the first document G1 and the leading edge of the second document G2 can be reduced to 0 mm.

  Alternatively, the conveyance timing of the preceding document G1 (first document G1) and the second document G2 is adjusted in advance based on the detection result of the paper timing sensor OUT72 and the detection result of the paper timing sensor IN73, and the preceding document The distance between G1 (first original G1) and second original G2 may be close to 0 mm.

  In ACT 258 in FIG. 7, when the second original G2 is conveyed to the READ original glass 110a following the preceding original G1 (first original G1), the main body controller 121 in ACT 230 in FIG. Wait for a certain time. When the document G2 is transported a certain distance after a certain period of time has elapsed, in ACT 231, the main body control unit 121 starts reading an image on the surface of the document G2 by the scanner 110.

  Thereafter, in ACT 232 of FIG. 6, the CPU 130 waits for the paper discharge sensor 78 to be turned on. When the leading edge of the document G2 reaches the position of the paper discharge sensor 78 and the paper discharge sensor 78 is turned on, in ACT 233, the CPU 130 turns on the paper discharge motor 88 and rotates the paper discharge roller 53. In the case of double-sided scanning, in ACT 237, the main body control unit 121 starts scanning the image on the back side of the document G2 using the CIS 60. After the paper discharge sensor 78 is turned on, the main body control unit 121 waits for a certain period of time in ACT 238. After a predetermined time has elapsed, in ACT 241, the main body control unit 121 ends the image reading of the surface of the document G 1 by the scanner 110.

  When the trailing edge of the document G2 passes through the roller 51 and the reading sensor 77 is turned off, the CPU 130 turns off the READ motor 87 and the intermediate OUT motor 84 in ACT242 in FIG. Further, after a predetermined time has elapsed after the reading sensor 77 is turned off, the main body control unit 121 ends the image reading of the back surface of the document G2 by the CIS 60.

  Thereafter, in ACT 260 of FIG. 8, the CPU 130 determines whether or not the document G2 is the final document, and when the document G2 is the final document (for example, when the empty sensor 70 is turned off after the document G2 is fed), The CPU 130 executes a final document discharge operation. That is, the CPU 130 performs an operation of turning off all the motors and solenoids and ending the document image reading and conveying control process.

  That is, in ACT 261 in FIG. 8, the CPU 130 waits for the paper discharge sensor 78 to be turned off. After the paper discharge sensor 78 is turned off, the CPU 130 continues to turn on the paper discharge motor 88 for a predetermined time and conveys the original G2 for a predetermined distance. When the paper discharge motor 88 is kept on for a predetermined time and the original G2 is conveyed for a predetermined distance, in ACT 263, the CPU 130 turns off all the motors and solenoids. This completes the control process for conveying two originals G.

  Next, a control process for reading the image by conveying the third original G3 will be described. If the CPU 130 determines in ACT 260 of FIG. 8 that the document G2 is not the final document, the CPU performs the following control process for the third document G3 without performing the above-described end operation.

  First, when the registration sensor 71 is turned on in the ACT 207 of FIG. 4 by the second original G2, the CPU 130 interrupts the third original G2 separately from the control process of the second original G2. Start feeding paper in parallel. However, the third document G3 waits for the paper feeding process until the trailing edge of the second document G2 passes through the registration sensor 71.

  In ACT 300 and ACT 301 in FIG. 4, the CPU 130 waits for the registration sensor 71 to be turned off when the trailing edge of the preceding second document G2 passes the registration sensor 71. When the registration sensor 71 is turned off in ACT 300, the CPU 130 turns on the pickup solenoid 81 and the paper feed motor 80 in ACT 206 of FIG. When the pickup solenoid 81 is turned on, the pickup roller 12 descends and comes into contact with the document G3 on the tray 11. When the paper feed motor 80 is turned on, as shown in FIG. 16, the pickup roller 12 rotates to start feeding the third original G3 from the tray. When the paper feed motor 80 is turned on, the separation roller 13 is rotated to transport the paper G3 fed from the tray 11.

  Then, in ACT 207 of FIG. 4, the CPU 130 waits for the registration sensor 71 to detect and turn on the document G3. When the leading edge of the document G3 reaches the position of the registration sensor 71, the registration sensor 71 detects the document G3 and turns on.

  When the registration sensor 71 is turned on, in ACT 208 in FIG. 4, the CPU 130 turns off the pickup solenoid 81 and the paper feed motor 80 after a predetermined time has elapsed since the registration sensor 71 was turned on. The original G3 comes into contact with the registration roller 14 and stops, and the leading edge thereof is aligned.

  Further, when the gate solenoid 83 is turned off, the gate 40 is switched to the direction of distributing to the OUT conveyance path 16. Thereafter, in ACT 211 of FIG. 4, the CPU 130 waits for a certain time to elapse. After a predetermined time has elapsed, in ACT 212, the CPU 130 determines whether the document G is an odd-numbered document or an even-numbered document.

  In this case, since it is the third original G3, the CPU 130 determines in ACT 265 that the preceding second original G2 is sandwiched between the pre-reading rollers 50, and the leading edge of the original G2 reaches the position of the pre-reading sensor 76. Then, it is confirmed whether or not the pre-reading sensor 76 is turned on. If the pre-read sensor 76 is on, the process proceeds to ACT 214.

In ACT 214 of FIG. 4, the CPU 130 turns on the registration motor 82 and the intermediate OUT motor 84 to rotate the registration roller 14 and the intermediate OUT roller 18 at a constant speed. When the registration motor 82 and the intermediate OUT motor 84 are turned on, the third original G3 is distributed to the gate 40 and proceeds to the OUT conveyance path 16. That is, the document G3 waits until the preceding document G2 enters between the pre-reading rollers, and then the document G3 is positioned between the registration roller 14 and the intermediate OUT in anticipation of the preceding document G2 being sandwiched between the pre-reading rollers. The roller 18 is conveyed to the OUT conveyance path 16.

  In ACT 215 of FIG. 5, the CPU 130 waits for the paper timing sensor OUT72 to turn on. When the document G3 reaches the position of the paper timing sensor OUT72 and the paper timing sensor OUT72 is turned on, in ACT 216, the CPU 130 keeps the registration motor 82 and the intermediate OUT motor 84 on for a certain period of time, and then the registration motor 82 and the intermediate timing. The OUT motor 84 is turned off.

  As shown in FIG. 17, the first original G1 is placed on the paper discharge tray 56, and the second original G2 runs on the READ original glass 110a to turn on the paper discharge sensor 78. The first document G3 stops before the pre-reading roller 50 in the OUT conveyance path 16. Thereafter, in ACT 218, the CPU 130 waits for reception of a conveyance request signal for the third original G 3 from the main body control unit 121.

  If the paper timing sensor OUT72 does not turn on even after a predetermined time has passed in ACT 217 of FIG. 5, as described above, the CPU 130 determines that the document G is jammed, and the display means (not shown) or the like Notify the occurrence of jam.

  In ACT 220 in FIG. 5, the CPU 130 waits for a predetermined time after the pre-read sensor 76 is turned on by the preceding document G2 (second document G2). When the predetermined time has elapsed, in ACT 221, the CPU 130 turns on the intermediate OUT motor 84 and the READ motor 87, and at a speed in accordance with instructions from the main body control unit 121, the intermediate OUT roller 18, the pre-reading roller 50, and the post-reading roller 51 and the pre-discharge roller 52 are rotated.

  Thereby, the CPU 130 starts conveying the leading edge of the preceding document G2 (second document G2) through the pre-reading roller 50 and the leading edge of the third document G3 by the pre-reading roller 50. Match timing. As in the documents G1 and G2 in FIG. 14, the third document G3 is a READ document glass in a state where the distance between the trailing edge α1 of the preceding document G2 and the tip β1 of the third document G3 is close to 0 mm. It is conveyed to 110a.

  In order to make the distance between the trailing edge α1 of the preceding document G2 (second document G2) and the leading edge β1 of the third document G3 close to 0 mm, the distance from the paper timing sensor OUT72 to the pre-reading roller 50 is set. The distance and the distance from the paper timing sensor IN73 to the pre-reading roller 50 are set to be equal as described above.

  Like G1 and G2 in FIG. 15, the third original G3 waits at a position advanced by a certain distance γ1 after turning on the paper timing sensor OUT72. When the trailing edge of the preceding document G2 passes through the paper timing sensor IN73 and advances a certain distance γ1, the READ motor 87 and the intermediate OUT motor 84 are turned on to transport the third document G3 toward the READ document glass 110a. . As a result, the distance between the trailing edge of the second document G2 and the leading edge of the third document G3 can be reduced to 0 mm.

  Alternatively, the conveyance timing of the preceding document G2 (second document G2) and the third document G3 is adjusted in advance based on the detection result of the paper timing sensor IN73 and the detection result of the paper timing sensor OUT72, and the preceding document The distance between G2 and the third original G3 may be close to 0 mm.

  In ACT 221 of FIG. 5, when the third document G3 is conveyed to the READ document glass 110a following the preceding document G2 (second document G2), the main body controller 121 in ACT 230 of FIG. Wait for a certain time. When the document G3 is conveyed by a certain distance after a certain time has elapsed, the main body control unit 121 starts reading an image on the surface of the document G3 by the scanner 110 in ACT 231.

  Thereafter, in ACT 232 of FIG. 6, the CPU 130 waits for the paper discharge sensor 78 to be turned on. When the leading edge of the document G3 reaches the position of the paper discharge sensor 78 and the paper discharge sensor 78 is turned on, in ACT 233, the CPU 130 turns on the paper discharge motor 88 and rotates the paper discharge roller 53. In the case of duplex scanning, in ACT 237, the main body control unit 121 starts scanning the image of the back side of the document G3 by the CIS 60.

  After the paper discharge sensor 78 is turned on, the main body control unit 121 waits for a certain time to elapse in ACT 238 of FIG. After a predetermined time has elapsed, in ACT 241, the main body control unit 121 ends the image reading of the surface of the document G 3 by the scanner 110. When the trailing edge of the document G3 passes through the roller 51 and the reading sensor 77 is turned off, the CPU 130 turns off the READ motor 87 and the intermediate OUT motor 84 in ACT242. Further, after a predetermined time has elapsed after the reading sensor 77 is turned off, the main body control unit 121 ends the image reading of the back side of the document G3 by the CIS 60.

    Thereafter, in ACT 260 of FIG. 8, CPU 130 determines whether document G3 is the final document. When the document G3 is the final document (when the empty sensor 70 is turned off after the document G3 is fed), the CPU 130 turns off all the motors and solenoids and ends the document image reading and conveying control process. I do.

  That is, in ACT 261 in FIG. 8, the CPU 130 waits for the paper discharge sensor 78 to be turned off. After the paper discharge sensor 78 is turned off, the CPU 130 continues to turn on the paper discharge motor 88 for a certain period of time and conveys the document G3 by a certain distance. When the paper discharge motor 88 is kept on for a predetermined time and the original G3 is conveyed for a predetermined distance, in ACT 263, the CPU 130 turns off all the motors and solenoids. Thereby, the control process for conveying three originals G is completed.

  In ACT 260 of FIG. 8, when the CPU 130 determines that the document G3 is not the final document, the above-described image reading control process of the document G2 is executed for the even-numbered document G without performing the paper discharge operation. For the odd-numbered document G, the above-described image reading control process for the document G3 is executed.

  According to this embodiment, when the original G is continuously read, two transport paths, the OUT transport path 16 and the IN transport path 17, are used. While the preceding document G is transported using one transport path, the succeeding document G is transported into the other transport path and waits in the other transport path. Here, the conveyance of the subsequent original G to the other conveyance path is that the preceding original G is sandwiched between the pre-reading rollers 50 provided in front of the READ original glass 110a of the scanner 110. It is done with a plan.

  Therefore, when the succeeding document G is waiting in the other transport path, the preceding document G is always sandwiched between the pre-reading rollers 50. Therefore, even if a jam occurs during the continuous conveyance of the original G and the preceding original G and the subsequent original G remain in the OUT conveyance path 16 and the IN conveyance path 17, the user can Which of the two remaining originals G is the preceding original G (which is sandwiched between the pre-reading rollers 50) and which is the subsequent original G (which is not sandwiched between the pre-reading rollers 50). The two sheets remaining in the transport path can be returned to the tray 11 in the correct order.

  In addition, the timing at which the preceding document G passes through the scanner 110 coincides with the timing at which the succeeding document G is conveyed to the scanner 110, and the distance between the preceding document G1 and the succeeding document G is reduced to 0 mm. In this state, the original G is continuously conveyed. Therefore, even if the conveyance speed of the original G is not increased, the conveyance of the original by the ADF 10 can be improved, and the image reading speed by the scanner 110 and thus the productivity of the image forming apparatus using the scanner 110 can be improved. In addition, it is possible to prevent the original G from being damaged when the conveyance speed is increased, or to suppress noise.

  The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, the shapes and structures of the plurality of transport paths are not limited. Also, the distance between the preceding document and the following document is not limited, but the closer the document is to 0 mm, the higher the document transportability. Further, the structure of the image reading unit for reading the document is also arbitrary. In the embodiment, in order to further reduce the size of the apparatus, a smaller CIS may be used instead of the scanner for reading the surface of the document.

The above-described embodiments are presented as examples and are not intended to limit the scope of the invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. The scope of the invention is included in the gist of this embodiment and its modifications, and is also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... Automatic document conveying apparatus 11 ... Document tray 12 ... Pickup roller 13 ... Separation roller 14 ... Registration roller 16 ... OUT conveyance path 17 ... IN conveyance path 18 ... Intermediate OUT roller 28 ... Intermediate IN roller 40 ... Gate 50 ... Pre-reading roller 51: Post-reading roller 56 ... Discharge tray 60 ... Contact image sensor 71 ... Registration sensor 72 ... Paper timing sensor OUT
73 ... Paper timing sensor IN
76: Pre-reading sensor 90 ... ADF open / close detection sensor 100 ... Image reading device 110 ... Scanner 110a ... READ document glass 110d ... CCD

Claims (10)

A paper feed unit that feeds documents one by one with an image read by the image reading unit;
A first conveyance unit that conveys a document fed by the paper feeding unit in the direction of the image reading unit via a first conveyance path;
A second conveyance unit that conveys a document fed by the sheet feeding unit in a direction toward the image reading unit via a second conveyance path different from the first conveyance path;
A third transport unit that alternately sandwiches the documents transported by the first transport unit and the second transport unit and transports them to the image reading unit;
A determination unit that determines that a document is sandwiched between the third conveyance unit;
The document fed by the sheet feeding unit is alternately distributed and sent to the first transport path and the second transport path, and when there is a preceding document, the determination unit determines that the preceding document is A document sorting and conveying unit that feeds a subsequent document to a conveyance path in which the preceding document is not fed out of the first and second conveyance paths after it is determined that the sheet is nipped; A feature of the automatic document feeder.   The third transport unit includes a pair of transport rollers, and transports the documents transported by the first transport unit and the second transport unit alternately between the transport rollers one by one. 2. The automatic document feeder according to claim 1, wherein   The determination unit determines that a document is sandwiched between the conveyance rollers by detecting a document conveyed by the conveyance roller by a pre-reading sensor provided between the conveyance roller and the image reading unit. The automatic document feeder according to claim 2, wherein:   The document sorting and conveying unit aligns the leading edge of the document fed by the paper feeding unit and has registration rollers in the first conveyance path and the second conveyance path. 4. The automatic according to claim 3, wherein when there is a document, the preceding document is detected by the pre-reading sensor, and then the succeeding document is sent to the first transport path or the second transport path. Document transport device.   5. The automatic document feeder according to claim 4, wherein the document sorting / conveying section has a gate that alternately sorts the document fed by the registration roller into the first transport path and the second transport path.   The paper feeding unit includes a tray on which a plurality of documents are stacked, a pickup roller that picks up the documents stacked on the tray, and a separation roller that separates and transports the documents picked up by the pickup roller one by one. The automatic document feeder according to claim 1, further comprising:   The document sorting / conveying unit is provided between the registration roller and the separation roller, and detects that the document conveyed by the separation roller has reached the registration roller and has passed through the registration roller. The pick-up roller and the separation roller have a registration sensor, and start feeding a subsequent document after the first registration sensor detects that a preceding document has passed through the registration roller. The automatic document feeder according to claim 6. The first transport unit has a first intermediate transport roller in the middle of the first transport path, and the second transport unit has a second intermediate transport roller in the middle of the second transport path, The first intermediate conveyance roller and the second intermediate conveyance roller cooperate with the third conveyance unit to convey the original from the first conveyance path or the second conveyance path to the image reading unit. The automatic document feeder according to claim 1.   The first intermediate conveyance roller and the second intermediate conveyance roller are arranged so that when there is a preceding document on one conveyance path of the first conveyance path or the second conveyance path, 9. The automatic document feeder according to claim 8, wherein after waiting for the document, the subsequent document is transported with the trailing edge of the preceding document and the leading edge of the succeeding document being brought close to each other. An image reading unit for reading an image of a document;
A paper feeding unit that feeds documents one by one with images read by the image reading unit;
A first conveyance unit that conveys a document fed by the paper feeding unit in the direction of the image reading unit via a first conveyance path;
A second conveyance unit that conveys a document fed by the sheet feeding unit in a direction toward the image reading unit via a second conveyance path different from the first conveyance path;
A third transport unit that alternately sandwiches the documents transported by the first transport unit and the second transport unit and transports them to the image reading unit;
A determination unit that determines that a document is sandwiched between the third conveyance unit;
The document fed by the sheet feeding unit is alternately distributed and sent to the first conveyance path and the second conveyance path, and when there is a preceding document, the detection unit detects the preceding document. And a document sorting and conveying section that feeds a subsequent document to a conveyance path in which the preceding document is not fed out of the first and second conveyance paths after being detected. apparatus.

Images