JP2009200677A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the image reading apparatus capable of changing the paper discharge speed with the original document length at the time of reading of mixed original documents, and easily putting the original documents in order after the paper discharge. <P>SOLUTION: The maximum size of an original document detected by a sensor 50 on an original mounting platform 5 is used as a reference. Specifically, if an A3 original document is the maximum size, a control portion 101 uses the discharge speed of the A3 original document as a reference discharge speed. A plurality of sensors 53 installed in a conveyance way F detect the original document length of the sub scanning direction, and check whether an original document is shorter than A3 or not. The control section 101 controls an original document conveyance roller driving motor through a driver 108, and increases the discharge speed. Thereby, even if a read original document is shorter than the maximum size original document, the read original document is kicked out to outside and the end of the read original document can be made in agreement with the maximum size original document. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image reading apparatus that facilitates document alignment after paper discharge by changing the paper discharge speed according to the length of the original when reading mixed originals.

  In recent years, an image reading apparatus is equipped with an automatic document feeder and can read a large amount of documents in a short time. In this case, it is possible that originals of different sizes, color or monochrome originals, etc. may coexist, and even if the user does not sort, an apparatus that automatically performs optimal reading settings and performs reading processing has appeared. Yes.

For example, in Patent Document 1 described later, when a read original is a single-sided original or a double-sided original, a color original, a case where a color original and a monochrome original are mixed, and a case where originals of different sizes are mixedly loaded. 1 shows an image reading apparatus, an image reading method, and an image forming apparatus that can efficiently read an original and have extremely high productivity. Specifically, the original image is read while feeding the read original document by the transport mechanism, and the first reading unit arranged to read one surface of the original and the same surface as the surface read by the first reading unit are arranged. And a second reading unit arranged on the downstream side of the first reading unit so as to read. In either case of the single-sided original or the double-sided limit, it is determined whether the image read by the first reading unit is color or monochrome, and the reading speed of the second reading unit is switched.
JP 2002-223339 A

  However, Patent Document 1 does not describe the alignment of documents on the document discharge tray when a mixed document is read. Therefore, when documents of different sizes are mixed, the documents discarded on the document discharge tray after reading are not aligned at all, and the user needs to align the documents.

  In view of such circumstances, the present invention is intended to provide an image reading apparatus that facilitates document alignment after paper discharge by varying the paper discharge speed according to the document length when reading a mixed document.

The present invention provides a document placement table on which a document to be read is placed, a conveyance path for transporting the document to be scanned, a document reading unit for reading a document placed on the document placement table, and a document that has been read is discharged. An original reading apparatus having a discharge unit for performing
When reading a document of mixed sizes, the document discharge speed from the transport path to the discharge unit is switched according to the document length in the transport direction, and the document is discharged with its leading end aligned. And

  The document length may be the length of the document reading unit in the sub-scanning direction.

  Further, a detecting unit for detecting the maximum document length of the document placed on the document placing table may be provided, and in this case, the read document according to the ratio between the detected maximum document length and the read document length. The discharge speed is switched. And when the said ratio becomes large, the discharge speed | rate of a reading original document is made quick.

  The conveyance path is either a straight path or a reverse path.

  According to the present invention, when a document having mixed sizes is read, the document discharge speed from the conveyance path to the discharge unit is switched according to the document length in the conveyance direction, and the document is discharged with its leading end aligned. Therefore, even when a mixed document that has been read is discharged, the document is aligned in the same manner as it is placed on the document table, so that the user can easily align the document after reading. be able to.

  A detection means for detecting the maximum document length of the document placed on the document placement table is provided, and when the ratio between the detected maximum document length and the read document length increases, the read document discharge speed is increased. Documents with a long length can be moved forward, documents with a short length can be moved far away, and the documents discharged to the discharge section can be aligned with the leading edges aligned.

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

  As shown in FIG. 1, the document reading apparatus 100 according to the first embodiment of the present invention automatically feeds a document along a document transport path F (hereinafter referred to as “ADF”). 1, a first image reading unit 10 that reads an image on the front side of the conveyed document, and a second image reading unit 20 that reads an image on the back side of the conveyed document.

  The first image reading means 10 is a reduction optical system image reading means comprising a light source 11, first to third mirrors 12a, 12b, 12c, a lens 13 and a CCD (image sensor) 14, and the second image reading means. The means 20 is a reduction optical system image reading means comprising a light source 21, first to fourth mirrors 22 a, 22 b, 22 c, 22 d, a lens 23 and a CCD (image sensor) 24. The second image reading unit 20 is unitized so that the light source 21, the first to fourth mirrors 22a, 22b, 22c, 22d, the lens 23, and the CCD 24 form one aggregate.

  A document reading apparatus 100 shown in FIG. 1 is provided on the upper portion of a copying machine (not shown), and mainly includes an ADF 1 that houses second image reading means 20 and a main scanning section that houses first image reading means 10. It consists of two.

  The ADF 1 and the main scanning unit 2 are connected by a hinge (not shown), and the ADF 1 can be opened and closed with respect to the main scanning unit 2 by the rotation of the hinge. The main scanning unit 2 mainly includes a housing 3, a platen plate 4 made of a transparent glass plate, and first image reading means 10 accommodated in the housing 3.

  The first image reading means 10 is mainly composed of a light source unit 15 that holds a light source 11 and a first mirror 12a, a mirror unit 16 that holds a second mirror 12b and a third mirror 12c, a lens 13 and a CCD 14.

  The main scanning unit 2 includes a document fixing method in which a user places a document on the platen 4 and reads a document image, and a document moving method in which a document image is read while the document is automatically conveyed by the ADF 1. Both types are supported.

  When reading an original image by the original fixing method, the light source unit 15 and the mirror unit 16 move to home positions corresponding to the original fixing method, respectively. Thereafter, the light source unit 15 scans the image of the original by moving in the sub-scanning direction (left and right with respect to the paper surface) at a constant speed while irradiating the original with light. Similarly, it moves in the sub-scanning direction at a moving speed that is 1/2 of the moving speed.

  The light irradiated from the light source unit 15 and reflected from the document is reflected by the first mirror 12a provided in the light source unit 15, and then the light path is changed by 180 ° by the second and third mirrors 12b and 12c of the mirror unit 16, and the third The light reflected from the mirror 12c forms an image on the CCD 14 via the lens 13 and is converted into electrical image data.

  On the other hand, when the original image is read by the original moving method, the light source unit 15 and the mirror unit 16 remain stationary at the home position shown in FIG. 1 and the original conveyed by the ADF 1 so as to pass above the home position. The light is irradiated from the light source 11 to scan the image, and the light reflected from the surface side of the original is reflected by the first mirror 12a in the same manner as the original fixing method described above, and then the second and second mirror units 16 The optical path is changed by 180 ° by the third mirrors 12b and 12c, formed on the CCD 14 through the lens 13, and converted into electrical image data.

  As shown in FIG. 1, the ADF 1 mainly feeds the originals placed on the original placement table 5 one by one into the ADF 1, and conveys the called originals along the original conveyance path F. The unitized second image reading means 20 is composed of a plurality of pairs of conveying rollers 7, a registration roller 8 for adjusting the paper feed timing, and a paper discharge roller 9 for discharging the document after image reading to the discharge tray 30. It is disposed so as to be accommodated in the document conveyance path F that draws an arc in a U shape.

  The second image reading means 20 includes a first mirror 22a, a second mirror 22b, a third mirror 22c, a fourth mirror 22d, a lens 23, and a CCD 24, and these members form a single unit. It is unitized by being accommodated in the housing 26. In the second image reading unit 20, the light source 21, the lens 23, and the CCD 24 are the same as those constituting the first image reading unit.

  As described above, the second image reading unit 20 reads the image on the back side of the document conveyed on the document conveyance path F when the user requests double-sided reading. Specifically, after the image on the front side of the document is read by the first image reading unit 10, the second image reading is performed while the document is being transported along the document transport path F toward the discharge tray 30. It passes under the light source 21 of the means. At this time, the light source 21 of the second image reading unit 20 emits light toward the back side of the document, and the light reflected from the back side of the document passes through the reading window 32 formed of a transparent member such as glass. Then, the optical paths are sequentially changed by the first to fourth mirrors 22a, 22b, 22c, and 22d, and then imaged on the CCD 24 through the lens 23 and converted into electrical image data.

  Further, the lower surface of the ADF 1 serves as a pressing plate 28 that presses a read document placed on the platen plate 4 of the main scanning unit 2 from above. The pressing plate 28 is a lid 29 that can be opened at a portion facing the light source 21 of the first image reading means 20.

  The document placing table 5 is provided with a document sensor 52 for detecting the presence or absence of a placed document, and document length sensors 50-1 and 50-2 for detecting the document length in the document transport direction. ing. Further, the document placing table 5 is provided with a document guide 51 that regulates the lateral direction of the document. By moving the document guide, the volume 50-3 is rotated and the resistance value of the volume is distorted. The control unit 101 shown in FIG. 2, which will be described later, reads the resistance value with an A / D terminal so that the lateral width of the placed document can be detected.

  Optical sensors 53-1, 53-2, 53-3, 53-4, 53-5, 53-6, 53-7 for detecting the position of the conveyed document are provided in the conveyance path for conveying the read document. , 53-8, and the conveyance speed of the document can be detected by the detection timing of each sensor.

  FIG. 2 is a block diagram schematically showing the main part of the electrical configuration of the document reading apparatus 100 according to the present embodiment.

  The document reading apparatus 100 according to the present embodiment mainly includes a control unit 101, a scanner unit 102, an image processing unit 103, a storage unit 104, a communication unit 105, an operation panel unit 106, a driver 107 for driving and controlling a document scanning unit drive motor 107a, The driver 108 is configured to drive and control the document transport roller driving motor 108a.

  The control unit 101 is a part that manages operation control of the entire apparatus, and is configured by a CPU, a ROM, a RAM, and the like (not shown).

  The scanner unit 102 constitutes an optical scanning system of the first and second image reading units 10 and 20 shown in FIG. The CCDs 14 and 24 of the first and second image reading means 10 and 20 are optical reduction type CCDs (Charge Coupled Devices) in the above description, but they may be CIS (Contact Image Sensor) of equal magnification optical type.

  The image processing unit 103 converts the optical data read by the first image reading unit 10 or the second image reading unit 20 into electrical image data in units of pages.

  The storage unit 104 is composed of, for example, a RAM, an EEPROM, a hard disk, an MO, and the like, and stores data under control controlled by the control unit 101 and various input instruction contents. The storage unit 104 includes an area that functions as a document image storage unit that stores a document image read by the scanner unit 102 and a document storage unit that stores a document including a converted character string code. And the sensors 50, 52, and 53 shown in FIG. 1 are also provided.

  The communication unit 105 is a communication unit that performs bidirectional communication with an external device 200 such as a connected computer or printer, and transmits data processed by the image processing unit 103 to the external device 200. In addition, a memory for expanding the data transmitted from the external device 200 into data that can be handled by the present apparatus is provided.

  Although not shown, the operation panel unit 106 is arranged on the front side of the document reading apparatus 100 shown in FIG. Specifically, the main scanning unit 2 is extended to the front side from the ADF 1 and is disposed on the upper surface portion thereof. The operation panel unit 106 is used when inputting an operation mode (designation such as single-sided reading or double-sided reading) at the time of document reading.

  The document scanning unit drive motor 107a is a motor for moving the light source unit 15 and the mirror unit 16 in the sub-scanning direction at an appropriate speed when reading a document image by the document fixing method. The driver 107 appropriately controls the drive.

  The document transport roller driving motor 108 a is a motor that drives each of the rollers such as the calling roller 6, the transport roller 7, the registration roller 8, and the paper discharge roller 9 disposed in the document transport path F, and is controlled by the control unit 101. The drive is appropriately controlled by the driver 108.

  FIG. 3 is a view of the document placing table 5 of the document reading device as viewed from above, and shows a state in which the mixed documents 300a, 300b, and 300c are placed in this order from the top. The length of the document in the transport direction is 300b <300a <300c, and the width of the document is 300a <300b = 300c. The document guide 51 is set to the document width in order to align the horizontal direction of the documents 300b and 300c. In FIG. 3, the original 300 a is placed in contact with the upper original guide 51.

  FIG. 4 is a diagram showing the state of the mixed originals 300a, 300b, and 300c. A) shows the state of the originals 300a, 300b, and 300c placed on the original placing table 5, and B) and C) show the discharge tray 30. 3 shows an ideal stacking state of the discharged originals. B) is a document ejected from the document table 5 through the reverse path, and C) is a document ejected through the straight path. In either case, the leading edge of the document is aligned in the same state as before reading. Yes.

  FIG. 5 shows the application of the document discharge applied to the present invention. By switching the document discharge speed in accordance with the length of the document, the leading end of the document is substantially matched, so that reading is performed. This has the effect of facilitating the organization of the finished manuscript. A) shows the state of the originals 300a, 300b, 300c placed on the original placing table 5, B) the original ejected from the original placing table via the reverse path, and C) ejected via the straight path. The manuscript is shown.

  FIG. 6 shows an arrangement position of the sensor mounted on the document placing table. The document sensor 52 for detecting the presence or absence of the document 300 placed on the document placing table 5 and the document length in the document transport direction. Document length sensors 50-1 and 50-2 are provided. Further, the document placing table 5 is provided with a document guide 51 that regulates the lateral direction of the document 300. When the document guide is moved, the volume 50-3 rotates and the resistance value of the volume changes. The control unit shown in FIG. 2 reads the resistance value at the A / D terminal, so that it is possible to detect a standard size recording paper by detecting the lateral width of the placed document 300.

  FIG. 7 shows the sheet size that is guided based on the conditions detected by the original length detection sensors 50-1 and 50-2 and the original width detection sensor 50-3. This data is stored in the storage unit 104, and the control unit 101 specifies the maximum standard size among the placed documents from the detection results of the detection sensors 50-1, 50-2, and 50-3, Specify the maximum document length.

  FIG. 8 and FIG. 9 are diagrams showing sensors provided in the document conveyance path and the document conveyance state. The document 300 is conveyed while controlling the conveyance speed by a pulse motor. By detecting the leading edge or the trailing edge of the document 300 by a sensor 53 disposed at a predetermined position, a more accurate document position is detected. I can do it. In the present invention, since the read original is a mixed-size original, only the maximum original size is detected in a state where the original is placed on the original table 5, and the size of each original cannot be detected. Therefore, the length of the document 300 being conveyed is detected by the document detection sensor 53 provided in the conveyance path F.

Although any sensor provided in the paper conveyance path F may be used, in the case of FIGS. 8 and 9, after the sensor 53-6 in front of the document reading position detects the leading edge of the read document (FIG. 8). The sensor 53-4 detects the trailing edge of the read document (see FIG. 9), and the length of the read document can be detected based on the document conveyance speed and the sensor disposition distance.
In the above example, a plurality of sensors are used. However, the leading edge and the trailing edge of the document may be detected by one sensor.

  As shown in FIGS. 4 and 5, the feature of the present invention is to align and align the leading end of the original after reading the mixed original, and when the original after reading is discharged outside the apparatus. This can be achieved by varying the discharge speed of the.

  First, the maximum document size detected by the sensor 50 on the document table 5 is used as a reference. Specifically, if the A3 document has the maximum size and the maximum document length, the control unit 101 sets the discharge speed of the A3 document as the reference discharge speed. The document length in the sub-scanning direction is detected by a plurality of sensors 53 installed in the conveyance path F to confirm whether the document is shorter than A3, and the control unit 101 activates the document conveyance roller drive motor via the driver 108. Control to increase the discharge speed. As a result, when the read original is shorter than A3, the discharge speed to the outside of the apparatus is increased, and the original is “kicked out”, whereby the leading end can be matched with the maximum-size original. The discharge speed depending on the length of the original can be calculated by the ratio of the original length obtained by detecting the running length and the A3 original length (420 mm).

For example, when the read original is B4-R detected:
Standard discharge speed 600 (mm / s) * ratio 1.15 (= 420/364) = 692.31 (mm / s)

When the scanned document is A5 detected:
Standard discharge speed 600 (mm / s) * ratio 2.84 (= 420/148) = 1702.70 (mm / s)

  When the maximum document size detected on the document loading table is A4-R, A4-R is set as the discharge reference speed, and the discharge speed is increased when the length of the sub-scanning direction is shorter than A4-R.

When the scanned document is B5-R detected:
Standard discharge speed 600 (mm / s) * ratio (= 297/257) = 693.39 (mm / s)

  Further, when the maximum size detected in the document stacking table 5 is A3, the discharge control change A3 is set as the reference discharge speed only when the running length is less than half the document size detected in the document tray, When the document length in the sub-scanning direction is less than half of A3, the discharge speed is increased. The following discharge speed can be calculated by the ratio of the document length obtained by detecting the running length and the A3 document length (420 mm).

As shown in FIGS. 8 and 9, a process for calculating the document length based on ON / OFF of the detection sensor 53, the number of document feeding motor steps, the time, and the distance between the sensors will be described.
After the document conveyance sensor 53-6 is turned on, the motor steps until the document conveyance sensor 53-4 is turned off are counted. Then, the document running length is

  Document travel length = motor distance of one step * number of motor steps + (distance between document conveyance sensor 53-6 and document conveyance sensor 53-4)

  As described above, when a mixed original is set, the original that has been read is changed by changing the discharge speed to the outside of the machine based on the maximum size of the original placed and the length of the original being conveyed. The tip of each can be made substantially the same position.

  In the present invention, it is possible to simultaneously read the front and back images when the document is conveyed, but the reading positions on the front and back sides are made different in order to prevent the influence at the time of reading.

  As shown in FIG. 10, since the front side is A part and the back side is B part, and the original image is read, when reading a double-sided original, the discharge speed is increased after the trailing edge of the original is detected by the sensor 53-8. As a result, the recording paper that has been read can be kicked out of the apparatus at high speed.

  In the case of a single-sided original, the recording paper that has been read can be kicked out of the apparatus at high speed by increasing the discharge speed after detecting the trailing edge of the original to be read by the sensor 53-7.

  It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

1 is a configuration diagram showing an embodiment of a document reading apparatus according to the present invention. 1 is a block diagram schematically showing a main part of an electrical configuration of a document reading apparatus according to an embodiment. 2 is a view of a document placing table of the document reading device as viewed from above. It is a figure which shows the ideal of the document mounting state on a document mounting base and a discharge tray. FIG. 4 is a diagram illustrating a document placement state on a document placement table and a discharge tray in the document reading apparatus of the present invention. It is a figure which shows the arrangement position of the sensor attached to the document mounting base. FIG. 6 is a diagram illustrating a paper size derived from detection results by a detection sensor for a document length direction and a detection sensor for a document width. FIG. 6 is a diagram illustrating a state where a sensor provided in a document transport path and a document transport state. FIG. 9 is a diagram illustrating a sensor provided on a document conveyance path subsequent to FIG. 8 and a document conveyance state. It is a figure which shows the case where a double-sided original is read.

Explanation of symbols

2 Main scanning unit 3 Housing 4 Platen plate 5 Document placing table 6 Roller 7 Transport roller 8 Registration roller 9 Paper discharge roller 10, 20 Image reading means 11 Light source 12a, 12b, 12c Mirror 13 Lens 15 Light source unit 16 Mirror unit 21 Light source 22a, 22b, 22c, 22d Mirror 23 Lens 26 Unit housing 28 Plate 29 Cover 30 Discharge tray 32 Reading window 50, 52, 53 Sensor 51 Document guide 100 Document reading device 101 Control unit 102 Scanner unit 103 Image processing unit 104 Storage unit 105 Communication unit 106 Operation panel unit 107, 108 Driver 107a Document scanning unit drive motor 108a Document transport roller drive motor 200 External device 300 Document

Claims (6)

A document placement table on which a scanned document is placed;
A conveyance path for conveying the read original;
A document reading unit for reading a document placed on the document placement table;
A document reading apparatus having a discharge unit for discharging a document that has been read,
When reading a document of mixed sizes, the document discharge speed from the transport path to the discharge unit is switched according to the document length in the transport direction, and the document is discharged with its leading end aligned. Document reading device.   The document reading apparatus according to claim 1, wherein the document length is a length of the document reading unit in a sub-scanning direction.   2. The document reading apparatus according to claim 1, further comprising detection means for detecting a maximum document length of the document placed on the document placement table.   4. The document reading apparatus according to claim 3, wherein the discharge speed of the read document is switched in accordance with a ratio between the detected maximum document length and the read document length.   6. The document reading apparatus according to claim 5, wherein when the ratio increases, the reading speed of the read document is increased.   6. The document reading apparatus according to claim 1, wherein the conveyance path is either a straight path or a reverse path.

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