JP2012085281A - Automatic document feeding device and document feeding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic document feeding device which can read a document that is difficult to discriminate a size before reading without passing the document through a read part for size discrimination.SOLUTION: An automatic document feeding device comprises a document table on which documents are loaded, a sheet detection sensor detecting a document loaded on the document table and having a first length in a feeding direction longer than a second length, a length detection sensor detecting a length in a feeding direction of a document during the document is fed, a first feeding path for feeding a document loaded on the document table to the reading part reading images of the document with a length from the length detection sensor to a reading part longer than the first length, a second feeding path different from the first feeding path for feeding a document loaded on the document table to the reading part and a switching part selectively switching between the first feeding path and the second feeding path. When the sheet detection sensor detects a document, the document is directed to the first feeding path.

Description

  Embodiments described herein relate generally to an automatic document conveyance device and a document conveyance method for conveying a document to an image reading apparatus.

  In an image reading apparatus equipped with an automatic document conveying device used for an image forming apparatus or the like, two paper conveying paths are provided, and when reading a plurality of originals, the originals are read into the two paper conveying paths, and the originals are distributed. Things that increase sex are known.

  Further, in an image reading apparatus provided with an automatic document conveying device, reading is performed after the size of the document is detected by the sensor on the tray on which the document is placed and the sensor in the paper conveying path.

JP 2009-253984 A

  However, papers with a long paper length in the direction of the paper transport path cannot be detected by the sensor before reading, and once passed through the reading unit without reading, the size is detected by the sensor. The document was conveyed and scanned.

  Therefore, as described above, even when the two paper conveyance paths are provided and the productivity of reading is improved, when reading a paper whose paper size cannot be detected before reading, the reading unit is passed a plurality of times to read the original. There was a problem that it was necessary and productivity became low.

  SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus capable of reading a document without passing the reading unit for size determination even for a document whose size is difficult to determine before reading. And

  An automatic document feeder according to an embodiment of the present invention includes a document placement unit on which a document is placed, and a length in a transportation direction of a document placed on the document placement unit being longer than a second length. A sheet detection sensor for detecting a document having a length, a length detection sensor for detecting a length in the transport direction of the document while the document is being transported, and a document placed on the document placement unit as an image of the document A first reading path that has a distance from the length detection sensor to the reading unit that is longer than the first length, and a document placed on the document placement unit. A second conveyance path that is different from the first conveyance path that conveys the document to the printing section, a switching unit that selectively switches between the first conveyance path and the second conveyance path, and the sheet detection sensor that detects the document. A controller that distributes the document to the first transport path by the switching unit. With.

1 is a schematic configuration diagram of an image reading apparatus. FIG. 3 is a block diagram showing a control system of the automatic document feeder. Flowchart of paper conveyance of the automatic document feeder in the first embodiment Continuation of the flowchart of paper conveyance of the automatic document feeder in the first embodiment Flowchart when a document is normally conveyed in an automatic document feeder Flowchart of paper conveyance of the automatic document feeder in the second embodiment

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

(First embodiment)
A first embodiment will be described with reference to FIGS.

  FIG. 1 is a cross-sectional view schematically showing an image reading apparatus to which an embodiment of the present invention is applied.

  The image reading apparatus 100 includes a scanner 110 serving as an image reading unit, and an automatic document feeder ADF (Auto-Document Feeder) 10 that transports a document G to the scanner 110. The scanner 110 includes a READ document glass 110a, a platen glass 110b for placing a document, 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 includes a document tray 11 serving as a document placement unit, a pickup roller 12 that takes out the document G from the document tray 11, a separation feeding roller 13 that prevents the document G from being double-fed, and a document. A registration roller 14 is provided for aligning the leading edges of the original G to be taken out from the tray 11 and conveyed.

  The document tray 11 has a paper detection sensor 21. The first sheet detection sensor 21 detects a sheet when a sheet having a first length in the sheet conveyance direction is placed on the document tray 11, but the first sheet detection sensor 21 has a first length in the sheet conveyance direction. In the case of a sheet having a second length shorter than the length, the sheet is provided on the document tray 11 at a position where the sheet is not detected. For example, the first length is the maximum length in the conveyance direction of the document that can be conveyed by the automatic document conveyance device 10.

  For example, an A3 size sheet can be considered as a sheet having a first length in the sheet conveyance direction, and an A4 size sheet can be considered as a sheet having a second length in the sheet conveyance direction.

  The automatic document feeder 10 has two conveyance paths, an OUT path 16 that is a first conveyance path reaching the scanner 110 from the registration roller 14 and an IN path 17 that is a second conveyance path reaching the scanner 110 from the registration roller 14. Have

  In the document transport path before branching from the document tray 11 to the OUT path 16 and the IN path 17, a length detection sensor 22 that detects the length of the document G in the transport direction and a length in a direction orthogonal to the document G transport direction. There is a width detection sensor 23 that detects the width. The length detection sensor 22 detects the length of the document G in the transport direction based on the time from when the leading edge of the document G is detected until the trailing edge of the document G is detected.

  In the OUT path 16, the distance from the length detection sensor 22 to the READ original glass 110 a that is the reading position of the original G is longer than the first length of the paper described above. Since the length from the length detection sensor 22 to the READ document glass 110a is longer than the first length, the size of the sheet having the first length in the sheet transport direction is the document G while the OUT path 16 is being transported. The length in the transport direction can be detected. The IN path 17 is shorter than the OUT path 16, and the length from the length detection sensor 22 to the READ original glass 110a is shorter than the first length.

  The automatic document feeder 10 includes a pre-reading roller 50 that conveys the original G that has passed through the OUT path 16 or the IN path 17 to the READ original glass 110a of the scanner 110, a post-reading roller 51 that discharges the original G from the READ original glass 110a, A pre-discharge roller 52, a discharge roller 53, and a discharge tray 56 are provided. A contact image sensor CIS (Contact Image Sensor) 60 is provided between the post-reading roller 51, the pre-discharge roller 52 and the discharge roller 52. For example, the CIS 60 may be provided in a conveyance path from the pre-discharge roller 52 to the discharge roller 53.

  In the READ original glass 110a, the optical mechanism 110c reads an image on the surface which is the first surface of the original G running on the glass surface. The CIS 60 can read the document G on the back surface, which is the second surface of the document G that travels through the READ document glass 110a.

  An empty sensor 70 for detecting the presence or absence of the document G is disposed above the document G pickup side of the document tray 11, and the document G reaches the registration roller 14 between the separation feeding roller 13 and the registration roller 14. A registration sensor 71 for detecting this is disposed. In the OUT path 16, a paper timing sensor OUT 72, 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 IN path 17, a paper timing sensor IN 73, which is a second timing sensor for detecting the driving timing of the registration roller 14 and the intermediate IN roller 28, is disposed.

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

  The paper feed motor 80 drives the pickup roller 12 and the separation paper feed roller 13 to rotate. When picking up the original on the original tray 11, the pickup roller 12 is swung by the pickup solenoid 81. A registration motor (RGT motor) 82 drives and rotates the registration roller 14. The gate solenoid 83 switches the gate 40 which is a transfer path switching unit. 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 path 16. 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 path 17.

  The intermediate OUT motor 84 drives and rotates the intermediate OUT roller 18. The intermediate IN motor 86 drives and rotates the intermediate IN roller 28. The READ motor 87 drives and rotates the pre-reading roller 50, the post-reading roller 51, and the pre-discharge roller 52. The paper discharge motor 88 drives and rotates the paper discharge roller 53.

  FIG. 2 shows a block diagram of a control system 120 mainly composed of the automatic document feeder 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 which is a control unit of the automatic document feeder 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, and a paper discharge sensor 78 are connected to the input side of the CPU 130. Further, a paper detection sensor 21, a paper length detection sensor 22, and a width detection sensor 23 are connected to the CPU 130.

  A pickup solenoid 81, a paper feed motor 80, an RGT 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.

  A sheet conveying method of the automatic document feeder according to the present embodiment will be described with reference to flowcharts shown in FIGS.

  After the power is turned on or when returning from the standby state, it is confirmed that the automatic document feeder 10 is closed (Act 1). When it is confirmed that the document feeder 10 is closed (No in Act 1), the CPU 130 detects the outputs of all the sensors and confirms that there is no paper jam (jam) in the automatic document feeder 10 (Act 2). ). If a paper jam is detected by the output of one of the sensors (No in Act 2), the CPU 130 notifies the main body control unit 121 of the paper jam, for example, and the control unit 121 is a publicly known image forming apparatus. A paper jam is displayed on a display (not shown) of the operation panel of FIG. On the other hand, when a paper jam is not detected from the output of any sensor (Yes in Act 2), the CPU 130 determines whether or not there is a document G on the document tray 11.

  When the document G is placed on the document tray 11, the empty sensor 70 is turned on. Accordingly, the CPU 130 next detects whether or not the empty sensor 70 is on (Act 3). If the empty sensor 70 is not ON (No in Act 3), the process returns to Act 1 and determines whether the ADF 10 is closed. On the other hand, when the empty sensor 70 is on (Act 3 Yes), the CPU 130 transmits a document on signal to the main body control unit 121, and then determines whether a paper feed request signal is received from the main body control unit 121. (Act 4).

  When the CPU 130 receives the paper feed request signal from the main body control unit 121 (Yes in Act 4), the CPU 130 determines whether or not the document G is detected by the output of the paper detection sensor 21 (Act 5). If no paper feed request signal has been received (No in Act 4), a standby state is entered.

  The fact that the paper detection sensor 21 has detected the original on the original tray 11 means that the original G has a first length in the transport direction.

  When the CPU 130 determines that the paper detection sensor 21 has detected the original G (Act 5 Yes), the CPU 130 turns off the gate solenoid 83 and moves the gate 40 so that the original G is conveyed to the OUT path 16. Thereafter, the CPU 130 turns on the pickup solenoid 81, turns on the paper feed motor 80, rotates the pickup roller 12 and the separation paper feed roller 13, and starts the paper feed operation of the original G to the OUT path 16. (Act 6).

  As the document G starts to be fed to the OUT path 16, the CPU 130 determines the paper size of the document G based on the detection results of the length detection sensor 22 and the width detection sensor 23 provided in the conveyance path of the OUT path 6. (Act 7).

  The CPU 130 drives the RGT motor 82 and the intermediate OUT motor 84 to transport the original G whose paper size has been determined in Act 7 to the READ original glass 110a which is the reading unit of the scanner 110 (Act 8).

  Next, the CPU 130 instructs the reading of the original G conveyed to the READ original glass 110a (Act 9).

  Thereafter, the CPU 130 drives the paper discharge motor 88 to discharge the original G to the paper discharge tray 56, and ends the processing (Act 10).

  If the CPU 130 does not determine that the paper detection sensor 21 has detected the original G in Act 5 (No in Act 5), the original G is normally conveyed. In this case, the document G on the document tray 11 has a second length that is shorter in the transport direction than the first length.

  In the normal conveyance in the present embodiment, the original G is alternately conveyed to the IN path and the OUT path. A flow for alternately distributing the document G into the IN pass and the OUT pass in the normal conveyance will be described with reference to the flowchart of FIG.

  When the normal detection of the automatic document feeder 10 is started when the paper detection sensor 21 does not detect the document G, the CPU 130 transports the document G to the IN path 17 or the OUT path 16 (Act 16). In the present embodiment, it is assumed that the first document G1 is conveyed to the IN path 17. In this case, the gate solenoid 83 is turned on, and the gate 40 is moved so that the first original G1 is conveyed to the IN path 17. Thereafter, the CPU 130 drives the paper feed motor 88 described above to start conveying the first original G1 to the IN path 17.

  Next, the CPU 130 determines whether or not the trailing edge of the first document G1 has passed through the registration sensor 71 and the registration sensor 71 has changed from on to off (Act 17). When the CPU 130 determines that the trailing edge of the first document G1 has passed through the registration sensor 71 (Yes in Act 17), the CPU 130 determines the presence or absence of the second document G2 based on the detection result of the empty sensor 70 (Act 18).

  When the CPU 130 determines that there is a second original G2 (Yes in Act 18), the second original G1 is transferred to a conveyance path different from the conveyance path where the first original G1 is conveyed in the IN path 17 and the OUT path 16. The original G2 is conveyed (Act 19). In the present embodiment, since the first original G1 is conveyed to the IN path 17, the second G2 is conveyed to the OUT path 16. In this case, the gate solenoid 83 is turned off, and the gate 40 is moved so that the second original G2 is conveyed to the OUT path 16. Thereafter, the CPU 130 drives the paper feed motor 80 described above to start conveying the second original G2 to the OUT path 16.

  As described above, the first document G1 is distributed to the IN path 17, the second document G2 is distributed to the OUT path 16, and a plurality of documents Gn are distributed to the two conveyance paths of the IN path 17 and the OUT path 16. The process ends. For the third and subsequent documents, the previous document is considered as the first document in the flowchart of FIG. 5, and is similarly distributed to the IN path 17 and the OUT path 16.

  As described above, since the original is alternately distributed to the IN path 17 and the OUT path 16 in the normal conveyance, the conveyance of the next original can be started before the previous original is discharged from the conveyance path. Therefore, it is possible to efficiently convey the document as compared to a case where a plurality of documents are conveyed using only one conveyance path.

  According to the above-described embodiment, in order to detect the paper size even for a document having a long length in the paper conveyance direction, it is not necessary to once pass through the reading unit and then convey it again to the reading unit, thereby reducing productivity. Absent. In addition, if the length of the paper in the paper conveyance direction is short, the original is distributed between the first conveyance path and the second conveyance path, so that high productivity can be maintained in reading the original.

(Second Embodiment)
A second embodiment will be described with reference to FIG.

  Hereinafter, the same reference numerals are used for the same parts as those in the above embodiment, and only the characteristic parts of this embodiment will be described. In this embodiment, a process when a user inputs in advance a mixed loading mode for reading a plurality of originals mixed with various paper sizes will be described.

  FIG. 6 shows a flowchart relating to a paper conveying method of the automatic document feeder in the present embodiment.

  Acts 1 to 3 are the same as the flowchart of FIG. 3 of the first embodiment. When the empty sensor is ON in Act 3 (Yes in Act 3), the CPU 130 determines whether there is an input of the mixed loading mode from the main body control unit 121 (Act 21). The instruction of the mixed loading mode is given by the user from, for example, an operation panel of the image forming apparatus, and the main body control unit 121 receives an input of the mixed loading mode. Thereafter, the main body control unit 121 transmits an input of the mixed loading mode to the CPU 130 of the automatic document feeder 120.

  When the CPU 130 receives the mixed loading mode input in Act 21 (Yes in Act 21), the CPU 130 sets the mixed loading mode (Act 22).

  When the mixed loading mode is set in Act 22, the CPU 130 controls the method of transporting the document G based on the detection result of the paper detection sensor 21 on the document tray 11, as in Act4 and subsequent steps in FIG. That is, when the paper detection sensor 21 detects the document G (when the document G has the first length), the document G is always printed on the OUT path 16. On the other hand, when the paper detection sensor 21 does not detect the original G (when the original G has the second length), as described above, for example, when there are two or more originals G, the immediately preceding original is conveyed. Referring to the road, the first sheet is distributed to the IN path 17 and the second sheet is distributed to the OUT path 16 or vice versa.

  If the CPU 130 does not accept the mixed loading mode input in Act 21 (No in Act 21), the document G is normally conveyed. The normal conveyance is the conveyance method described with reference to the flowchart of FIG. 5 of the first embodiment.

As in this embodiment, if the conveyance path is determined using the detection result of the paper detection sensor 21 on the document tray 11 only when the mixed mode is input from the user,
In the mixed loading mode in which the originals G of various paper sizes are mixed, an optimum conveyance path can be selected for each original. When the original G of a certain paper size is not conveyed, By performing the conveyance, the document can be efficiently conveyed.

  As mentioned above, although embodiment of this invention was described, this embodiment is shown as an example and is not intending limiting the range of invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 Automatic document feeder 11 Document tray 14 Registration roller 16 OUT path 17 IN path 21 Paper detection sensor 22 Length detection sensor 23 Width detection sensor 40 Gate 50 Pre-reading roller 51 Post-reading roller 56 Paper discharge tray 60 Contact image sensor 72 Paper Timing sensor OUT
73 Paper Timing Sensor IN
76 Pre-reading sensor 100 Image reading device 110 Scanner 110a READ document glass 130 CPU

Claims (10)

A document placement section for placing a document;
A sheet detection sensor for detecting a document whose first length is longer than a second length of a document placed on the document placement unit;
A length detection sensor for detecting the length of the document in the conveyance direction during document conveyance;
A first conveyance path that conveys a document placed on the document placement unit to a reading unit that reads an image of the document, and a distance from the length detection sensor to the reading unit is longer than the first length; ,
A second transport path different from the first transport path for transporting the document placed on the document placement section to the reading section;
A switching unit that selectively switches between the first transport path and the second transport path;
A control unit that distributes the document to the first conveyance path by the switching unit when the paper detection sensor detects the document;
An automatic document feeder characterized by comprising:   2. The automatic document feeder according to claim 1, wherein the first length is a maximum length in a conveyance direction of the document that can be conveyed by the automatic document feeder.   3. The automatic document feeder according to claim 1, wherein a distance from the length detection sensor to the reading unit is shorter than the first length of the second conveyance path.   When the paper detection sensor does not detect a document having a second length shorter than the first length and is placed on the document placement unit, the control unit causes the switching unit to connect the first conveyance path to the first conveyance path. 4. The automatic document feeder according to claim 1, wherein the document is alternately distributed to the second conveyance path. 5.   When a plurality of documents are placed on the document placement unit, the control unit has the first length or a second length shorter than the first length in the document transport direction. When the input of the mixed loading mode indicating that the document is included is received and the input of the mixed loading mode is received, the first conveyance path or the second conveyance path is based on the detection result by the paper detection sensor. 2. The automatic document feeder according to claim 1, wherein the document is distributed to each other.   When the paper detection sensor does not detect the second-length document placed on the document placement unit, the control unit causes the switching unit to convert the second-length document. 6. The automatic document feeder according to claim 5, wherein the automatic document feeder is alternately assigned to the first conveyance path or the second conveyance path. A sheet detection sensor provided in the document placement section and a plurality of transports that transport the document placed on the document placement section to the image reading section, at least having different lengths of the transport path from the length detection sensor to the reading section. In an automatic document feeder having a path and a switching unit that selectively switches the plurality of transport paths,
The paper detection sensor determines whether or not a document having a first length that is longer than the second length in the document conveyance direction is detected;
When the document placed on the document placement unit is detected by the sheet detection sensor, the switching unit causes the length of the conveyance path to be longer than the first length of the document by the switching unit. An original conveying method for an automatic original conveying apparatus, wherein an original is distributed to a long first conveying path.   8. The document conveying method of an automatic document feeder according to claim 7, wherein the first length is a maximum length in the document conveyance direction that can be conveyed by the automatic document feeder.   Receiving a mixed mode input indicating that a document having a second length shorter than the first length or the first length is included when reading a plurality of documents; When an input of the mixed loading mode is received, at least a document having the first length is distributed to the first conveyance path by the switching unit based on a detection result by the paper detection sensor. 9. A document conveying method for an automatic document feeder according to claim 7 or 8.   As the plurality of conveyance paths, in addition to the first conveyance path, a second conveyance path is provided, and when the sheet detection sensor does not detect the second-length document, the switching unit causes the first conveyance path to 9. A document conveying method for an automatic document conveying apparatus according to claim 8, wherein the document is alternately distributed to one conveying path and the second conveying path.

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