JP4872898B2 - Image reading apparatus, image forming apparatus, image reading apparatus control method, and image reading apparatus control program - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus, an image forming apparatus, an image reading apparatus control method, and an image reading apparatus control program, and more particularly to an image reading apparatus, an image forming apparatus, and an image reading apparatus provided with a reference surface as a reference for image correction And a control program for the image reading apparatus.

  2. Description of the Related Art Image forming apparatuses (MFP (Multi Function Peripheral), facsimile machines, copiers, multifunction machines, etc.) are provided with a scanner unit (image reading apparatus) for reading a document.

  2. Description of the Related Art There is known an apparatus that enables a scanner unit to simultaneously read both sides of a document. In this method, while a document is being conveyed, the front surface is read by a CCD (charge-coupled device) sensor, and the back surface is read by a CIS (contact image sensor). At the time of double-sided reading, both the CCD sensor and the CIS are stopped, and scanning is performed by conveying the original.

  In order to correct a CIS read image, a shading plate (opposite plate) is provided to face the CIS. Conventionally, as a shading plate, a flat plate or a columnar plate has been used.

  Patent Document 1 below discloses an image reading apparatus in which a cylindrical guide member having a guide surface and a shading surface is provided, and the guide surface and the shading surface are switched by rotating the guide member.

Patent Document 2 discloses an image reading apparatus in which a white guide member is retracted when a single-side reading paper is passed.
JP 2001-313794 A JP 2003-315934 A

  An object of the present invention is to provide an image reading apparatus, an image forming apparatus, an image reading apparatus control method, and an image reading apparatus control program capable of appropriately controlling a reference plane serving as a reference for image correction. Yes.

  In order to achieve the above object, according to one aspect of the present invention, an image reading apparatus includes a reading unit that reads a document and a reference surface that is provided opposite to the reading unit and serves as a reference for image correction of the reading unit. The image of the reference surface is read by the prism, the conveying unit that conveys the document between the reading unit and the polygonal column, the rotating unit that rotates the polygonal column on the axis that intersects the document conveying direction, and the reading unit, Correction means for performing a predetermined image correction; and a stopping means for stopping the rotation when the reading means reads data and acquires data outside the predetermined range before rotating the polygonal prism by the rotation means. Is provided.

  Preferably, the polygonal column has a guide surface that guides the conveyed document opposite to the reading unit, and the rotating unit rotates the polygonal column with a rotation axis orthogonal to the document conveying direction.

  Preferably, the canceling unit performs reading by the reading unit before starting the document reading operation.

  Preferably, the image reading apparatus further includes warning means for giving a warning when the rotation is stopped.

  Preferably, the image reading apparatus includes a mechanism for opening and closing between the polygonal column and the reading unit, and after the rotation of the polygonal column is stopped by the stopping unit, the polygonal column and the reading unit are opened and closed. Thereafter, the rotation of the polygonal column is started.

Preferably the image reading apparatus, before you feed the document by the conveying means, to return to the reference position polygonal by rotating means.

  Preferably, the image reading apparatus further includes a cleaning member for cleaning the polygonal column.

  Preferably, at least one of a white reference surface, a black reference surface, and a sheet passing surface is formed on the polygonal column.

  Preferably, the image reading apparatus further includes a second reading unit that reads a document surface different from the document surface read by the reading unit, and reads images on both sides of the document by one document transport operation by the transport unit.

  According to another aspect of the present invention, an image forming apparatus includes any of the image reading apparatuses described above.

  According to still another aspect of the present invention, a reading unit that reads a document, a polygonal column that is provided facing the reading unit and has at least a reference plane that serves as a reference for image correction of the reading unit, and a document, a reading unit, A control method of an image reading apparatus including a conveying unit that conveys between a polygonal column and a correcting unit that reads an image of a reference plane by a reading unit and performs predetermined image correction. A turning step for turning around the intersecting shafts, and a step for stopping the turning when the reading means reads data and acquires data outside a predetermined range before turning the polygonal column in the turning step. With.

  According to still another aspect of the present invention, a reading unit that reads a document, a polygonal column that is provided facing the reading unit and has at least a reference plane that serves as a reference for image correction of the reading unit, and a document, a reading unit, A control program for an image reading apparatus including a conveying unit that conveys between a polygonal column and a correcting unit that reads an image of a reference plane by a reading unit and performs predetermined image correction. A turning step for turning around the intersecting shafts, and a step for stopping the turning when the reading means reads data and acquires data outside a predetermined range before turning the polygonal column in the turning step. And let the computer run.

  According to these inventions, it is possible to provide an image reading apparatus, an image forming apparatus, an image reading apparatus control method, and an image reading apparatus control program capable of appropriately controlling a reference plane serving as a reference for image correction. It becomes possible.

  Hereinafter, an image reading apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  An image reading apparatus that reads both sides of a document image simultaneously has a mechanism for reading a back side image by CIS. Shading correction is performed before the image is read by CIS. A facing surface is provided at a position facing the CIS.

  The facing surface can be switched by rotating it with a motor or the like. Specifically, the facing surface is provided on the side surface of the polygonal column. In the present embodiment, a hexagonal column is used as the polygonal column. As the facing surface, three types of surfaces, a paper passing surface, a white shading surface (white reference surface), and a black shading surface (black reference surface) are prepared.

  At the start of the hexagonal column rotation (before the start), the image is read by CIS. By comparing the read image data with the default value of the image data on the facing surface, it is determined whether the document is photographed by CIS or the facing surface is photographed by CIS.

  When the document image is taken by CIS, the document exists at the CIS position. In this case, a warning for causing the operator (user) to remove the document is displayed on the operation panel. In this case, the opposing surface is not rotated. This prevents the original from being damaged by the rotation of the facing surface.

  Further, at the start of the document reading operation, the following operation is performed.

  -In single-sided scanning, at the start of reading (before starting), make sure that the opposing surface is the paper surface and return to the reference position. As a result, the original can be satisfactorily passed.

  In double-sided reading, in order to perform a shading operation, the opposite surface is set as a reference surface and returned to the reference position.

  In the present embodiment, a polygonal column is used as the shading plate. The shading accuracy can be improved by performing a plurality of samplings using a plurality of surfaces of the polygonal column. Thereby, the image quality can be improved.

  When shading is performed using a polygonal shading facing plate, it is necessary to perform sampling for shading at a position similar to the position through which the paper passes. That is, it is desirable that the position of the plane where sampling is performed at the time of shading correction is the same position as the position of the paper at the time of image reading. From this, the polygonal column is installed as close as possible to the CIS.

  The polygonal column includes two bottom surfaces and N (N> 2) side surfaces. The polygonal column has a side ridge (a line of intersection between the side surface and the side surface) where the side surface and the side surface intersect. The length from the central axis to the side surface of the polygonal column is shorter than the length from the central axis to the side ridge. That is, assuming a polygon which is a cross section when a polygonal column is cut by a plane parallel to the bottom surface, the distance from the center of the polygon to the side is shorter than the distance from the center of the polygon to the corner. . Further, the distance between opposite sides is shorter than the distance between diagonals.

  For this reason, it is necessary to make the paper traveling direction and the side surface of the polygonal column parallel to each other during paper feeding. If they are not parallel, the side edges of the polygon will interfere with the document. If the polygonal column stops at a position that is not parallel, passing the paper will damage the original. Further, when the original is stopped at the CIS position for some reason, the original may be damaged if the polygonal column is rotated.

  When a flat plate or a cylindrical plate is used as the shading plate, it is not necessary to consider such damage to the document. However, when a rotating polygonal column is used, it is necessary to consider the influence on the document.

  Therefore, in this embodiment, when starting the shading operation or starting the initial reference position return, image data is acquired by the CIS in front of the polygonal column. The acquired data is compared with default data or the like, and if it is out of the threshold range, a warning is given that there is a possibility that the document remains. The action after the warning is used to determine whether to start the operation.

  As a result, when the polygonal column is operated, even if there is a document between the CIS and the polygonal column, the document can be removed without further damage.

  [First Embodiment]

  FIG. 1 is a block diagram of an image forming apparatus equipped with an image reading apparatus and capable of color printing.

  The image forming apparatus 100 includes a scanner 200, an ADF (automatic document feeder) 300, a printer 400, a control device 500, and an operation unit 600.

  The scanner 200 is provided with a CCD 201 for surface reading and a scanner control unit 203.

  The ADF 300 is provided with a CIS 301 for reading the back surface and a document reading device controller 303.

  The printer 400 is provided with a laser diode (LD) 401 and a printer control unit 403.

  The control device 500 includes a reading processing unit 501 that processes signals from the CCD 201 and the CIS 301, a compression IC 503 that compresses image data, an image memory (DRAM) 505, and a DRAM control IC 507 that controls the image memory. A decompression IC 513 that decompresses image data, a write processing unit 515 that outputs an image with a printer, a non-volatile memory 511 that stores programs and constants, and an image control unit 509 that controls image processing are provided.

  The image memory 505 includes a compression memory 505a and a page memory 505b.

  The operation unit 600 is provided with an LCD (Liquid Crystal Display) 601 for displaying various types of information to the operator, and an operation control unit 603 including a touch panel and keys.

  The image forming apparatus reads both sides of a document at the same time using a CCD and a CIS.

  The image control unit 509 has a function of reading a reference plane image by the CCD 201 or the CIS 301 and performing predetermined image correction (shading correction or the like).

  FIG. 2 is a diagram illustrating a control target connected to the image reading device control unit 303 in the ADF 300.

  The image reading device (ADF) control unit 303 to which the CPU is attached and the ADF drive substrate 305 are connected in parallel or the like. The ADF drive substrate 305 performs output to the drive medium and sensor input, and exchanges information with the image reading device control unit 303.

  The ADF drive board 305 is connected to various motors 309, various sensors 311, and other loads 307.

  The various motors 309 include a paper feed / conveyance motor 309a, a document tray lift up / down motor 309b, and a CIS counter plate (hexagonal column) drive motor 303c.

  The various sensors 311 include a paper feed conveyance sensor 311a, a cover open / close detection sensor 311b, and a reference position detection sensor 311c for the CIS counter plate.

  Other loads 307 include a paper feed clutch 307a and a CIS lamp 307b.

  The ADF drive board 305 has a motor for feeding a document and a drive circuit for a CIS counter plate drive motor, and operates these motors by a drive signal from the image reading device control unit 303.

  In the image reading apparatus, a sensor for controlling the sheet passing timing is attached to the sheet passing path for document conveyance control. This is the paper feed sensor 311a. As a result, passage of a sheet through a predetermined location can be detected.

  The image reading apparatus is designed to perform an emergency stop when a paper jam occurs during document passing. In order to easily remove the original, the sheet passing path is opened and closed by a cover. This cover open / close detection is detected by the cover open / close detection sensor 311b. When it is detected by the sensor that there is no paper on the document passing path when all the covers are closed, the image reading apparatus becomes operable.

  FIG. 3 is a diagram illustrating a configuration of a control mechanism of the image reading device control unit 303.

  The CPU 303a is used for mechanical control. The CPU 303a includes a built-in ROM and RAM. The CPU 303a is connected to an SRAM 303b, an ASIC, or the like 303c via a bus. The ASIC can control the input / output of expansion and the motor. The SRAM 303b stores adjustment values and the like.

  FIG. 4 is a diagram illustrating an internal configuration of the ADF 300.

  The ADF 300 pulls the document placed on the document placement table 321 in the “A” direction, and reads the image on the surface of the document with the CCD 201 via the mirrors 205a to 205c. Further, the back side image is read by the CIS 301. The document that has been read is carried to a paper discharge tray 323.

  FIG. 5 is an enlarged view of a portion “B” in FIG.

  The sheet passing path is indicated by an arrow “D”. The document passes between the guide plate 335 and the CIS 301. A shading facing plate (hexagonal column) 331 is provided at a position facing the imaging position (reading position) of the CIS 301. The plane formed by the guide plate 335 and the shading facing plate (hexagonal column) 331 can be moved as indicated by an arrow “C”. As a result, the paper passing path is opened and closed, and the operator can take out the staying paper. The opening / closing of the cover is detected by a sensor.

  The CIS 301 is a CIS unit including a CIS and a light source. In the drawing, the CIS 301 is provided with light sources (lamps) on the left and right of the reading position (upstream and downstream in the paper passing direction), and illuminates the original.

  Reading with the CIS 301 must be performed reliably. For this reason, the apparatus is designed so that the original passes near the reading surface of the CIS. Further, it is necessary to design the hexagonal column 331 so as to be in the vicinity of the document passing position. When trying to satisfy these conditions, the document passing path becomes narrower. Depending on the rotation angle of the polygonal shading facing plate, the sheet passing path is shielded.

  A cleaning member 333 such as a brush is provided at a portion in contact with the shading facing plate (hexagonal column) 331. The brush 333 cleans dust such as paper dust of the original so as not to be affected during shading.

  The hexagonal column 331 is rotated by an axis (here, an orthogonal axis) that intersects the document conveyance direction.

  FIG. 6 is a cross-sectional view of the shading facing plate (hexagonal column) 331.

  The shading facing plate (hexagonal column) 331 includes a sheet passing surface (1) and a sheet passing surface (2) facing the sheet passing surface (1), a white surface (1) and an adjacent white surface (2), and a black surface (1) and an adjacent to it. A matching black surface (2) is provided.

  On the white and black surfaces, white and black plates are attached for shading. At the time of shading correction, shading correction is performed by irradiating the surface with light from a lamp and reading reflected light.

  The shading here includes black correction, white correction, gain correction, offset correction, and the like. Since each control is publicly known, no particular explanation is given here.

  The sheet passing surface is used as a guide on the sheet passing path when the document is passed. This is provided to prevent the white surface and the black surface from being scratched. This is because when shading, it is desirable to perform the shading operation as cleanly as possible.

  FIG. 7 is a diagram illustrating a reference position detection mechanism for a shading facing plate (hexagonal column).

  In order to detect the reference position, a sensor light-shielding plate 331b is mounted on a hexagonal column rotating shaft 331a. The reference position detection sensor 311c detects the passage of the sensor light shielding plate 331b and outputs an ON / OFF signal. The reference position is grasped by detecting the ON / OFF edge.

  The rotary shaft 331a can be rotated in the forward and reverse directions, and can be rotated on either side. However, in order to accurately detect the reference position, the reference position is detected only by rotation from one direction.

  FIG. 8 is a perspective view of a shading counter plate (hexagonal column), and FIG. 9 is a schematic view showing a driving mechanism thereof.

  The shading counter plate 331 having a plurality of surfaces 331d, 331e, 331f,... Is driven by a drive motor 309c (stepping motor) via gears 341a and 341b. The position can be detected by the sensor 311c described above.

  FIG. 10 is a flowchart showing rotation control (initial position return control) of the shading counter plate.

  In step S101, the state of the reference position detection sensor is confirmed. If it is on (when the sensor light shielding plate 331b shields the reference position detection sensor 311c), in order to reversely rotate the shading counter plate, the setting for reverse rotation side driving is made in step S102. Also, set the excitation state and set a timer for initial excitation.

  In step S103, a timer for initial excitation is waited. When the timer counts up, the process proceeds to S104, and a pulse is output for driving. The motor starts to rotate by the pulse output. The motor may be accelerated / decelerated to reduce time.

  When the motor starts to rotate, the input of the reference position detection sensor is monitored and the sensor waits for an off-edge of the sensor (S105). Moves to step S106 at the off edge of the reference position detection sensor, stops the pulse output for driving the motor, sets the excitation timer for holding the position, and sets the motor operation direction to the forward rotation side for the next operation. Set to.

  When the timer counts up in step S107, the process proceeds to step S110 to output a pulse for driving. In step S111, the on-edge of the reference position detection sensor is confirmed, and the process proceeds to step S112 by edge confirmation.

  In step S112, the pulse is stopped and an excitation timer for holding the stop is set. Next, in step S113, the process waits for the timer to count up. When the timer counts up, the process proceeds to step S114 and ends.

  If the reference position detection sensor is not turned on in step S101, in order to rotate the motor in forward direction in step S108, it is set for forward rotation side driving, in the excitation state setting, for initial excitation. Set the timer.

  In step S109, the process waits for the timer to count up. Since the description after step S110 is the same as described above, the description is not repeated here.

  With this flow, the return operation to the reference position is performed. The reference position is matched in the forward rotation direction to maintain accuracy.

  FIG. 11 is a flowchart showing the position control of the shading facing plate.

  The process of moving the shading counter plate to the target position is performed in white correction or light distribution correction in shading. Shading correction is performed when the power is turned on or when reading of a document is started. Since the method of moving the shading facing plate and the content of shading are known, no particular explanation will be given.

  In step S201, the current stop position of the shading counter plate is confirmed. When the power is turned on, the reference position is controlled by the flowchart of FIG. 10 so that the sheet passing surface (1) of FIG. 6 stops in a state of facing the CIS. The position of the shading counter plate is stored in the memory 511 or the like.

  In step S202, information on the target position is acquired by an instruction. In step S203, the distance to the target position (rotation angle, number of control steps) is calculated.

  In step S204, it is determined whether to rotate the motor forward or backward. This is to select the rotation of the one that can move quickly to the target position (the direction in which the moving distance is short).

  If the rotation is normal, the process proceeds to step S205, where pre-excitation is performed, the motor is advanced by a predetermined step, stopped, and post-excitation is performed to end.

  If it is reverse rotation (when it is faster to move by reverse rotation), reverse rotation processing is performed in step S206. In the case of reverse rotation, the operation up to the backlash adjustment operation is performed, and this processing is terminated.

  FIG. 12 is a flowchart of motor forward rotation processing.

  When performing normal rotation processing, excitation at the time of activation is performed in step S301, port setting for normal rotation direction operation, and initial excitation timer setting are performed. In step S302, the process waits for the initial excitation timer to count up.

  In step S303, a predetermined pulse is output to drive the motor. In step S304, it is confirmed whether or not the output of the predetermined pulse has been completed. If it has been completed, a post-excitation timer is set in step S305, and the timer counts up in step S306. When the timer counts up, the excitation is turned off in step S307 and the process ends.

  FIG. 13 is a flowchart of motor reverse rotation processing.

  When reverse rotation processing is performed, the start excitation is performed in step S401, the reverse rotation direction is set, and a timer for excitation is set. In step S402, the timer waits for a timer count-up. When the count-up is completed, a predetermined pulse for driving + pulse for backlash overrun is output in step S403.

  In step S404, it is confirmed whether the pulse has been output for the count. If the pulse is output, in step S405, the forward rotation direction is set, and the excitation timer is set. When the excitation timer counts up in step S406, the process proceeds to step S407.

  In step S407, a pulse for returning the overrun is output. When the completion of pulse output is confirmed in step S408, a post-excitation timer for maintaining the position is set in step S409. In step S410, the timer counts up. When the count is up, the process proceeds to step S411, the excitation is turned off, and the process ends.

  FIG. 14 is a diagram showing the position of the shading facing plate when the document is passed.

  When the document P is between the CIS 301 and the shading facing plate 331, if the surface of the shading facing plate 331 (the side surface of the hexagonal column) is parallel to the sheet passing path “D”, the document can be conveyed without any problem. it can. At the reference position, the surface of the shading facing plate 331 is parallel to the sheet passing path “D”.

  FIG. 15 is a diagram illustrating a state in which the shading facing plate 331 interferes with the document.

  In FIG. 15, the surface (side surface of the hexagonal column) of the shading facing plate 331 is not parallel to the sheet passing path “D”. This indicates a state where the return to the reference position is not sufficiently performed.

  If the document is transported in such a case, the document may come into contact with the ridge portion of the hexagonal column, and JAM may occur. Further, when the shading facing plate 331 is rotated in the state of FIG. 14, the shading facing plate 331 hits the document P and damages the document.

  For this reason, in the present embodiment, before the original is fed (before the reading operation is started), an operation of always returning to the reference position as shown in FIG. 14 is performed. That is, the processing in the flowchart of FIG.

  Further, before the shading counter plate 331 is rotated, it is confirmed whether the original P is between the CIS 301 and the shading counter plate 331.

  FIG. 16 is a flowchart showing a process for rotating the shading counter plate 331.

  The rotating operation of the shading counter plate is started when the power is turned on or when an instruction for copying is issued by the operator. This is to perform shading correction at power-on when the power is turned on, and to perform shading correction at the initial stage of reading at the time of copying.

  In step S001, at the CIS operation start event, the lamp in the CIS unit is lit to read an image in the CIS, waits for a time until the light quantity is stabilized, and the process proceeds to step S002.

  In step S002, image data is read by CIS. Here, data on the photographing surface is read in the same manner as in shading. In step S003, the read data is compared with the data on the surface of the shading counter plate 331. A white sheet is pasted on the white surface of the shading counter plate for shading correction, and a black sheet is pasted on the black surface.

  As a comparison target in step S002, a default value in initial adjustment may be used, or data such as a shading surface accumulated by data collection may be stored in a memory in advance and used. good. In any case, basic data of each surface of the shading counter plate 331 is stored, and the value is a comparison target.

  If the document stays on the CIS reading surface, a data value different from the stored data is acquired from the CIS. In this case, the operator is prompted for confirmation. Even if there is no document, a warning may be issued in the same manner when the sheet passing surface and the surface of the shading facing plate are not in a parallel relationship. In this case as well, priority is given to not damaging the document, and the operator is prompted for confirmation.

  That is, if the presence or absence of the document is uncertain, the process proceeds to step S005, and the CIS lamp is turned off. Thereafter, the process proceeds to step S006, where a warning is issued to the operator or the like on the operation panel or the like to urge the operator to check whether or not the document is pinched. In step S007, after the covers of the CIS portion of the image reading apparatus are opened, the process waits until it is detected that all the covers are closed. Thereafter, the process proceeds to operation S004.

  The processing in step S007 prompts the operator to perform a residual document confirmation operation by outputting a warning message, and regards that the operator has completed the confirmation work because the ADF cover has changed from the closed state to the open state. is there. Furthermore, when the state is changed from the open state to the closed state (when there are a plurality of covers, all are closed), the operation is shifted to the next operation.

  Although omitted in the flow, the warning message or the like is deleted when all the covers are closed.

  In step S004, the CIS shading counter plate is operated in a predetermined sequence when the power is turned on or when the job starts.

  Here, the determination in step S003 will be described in detail.

  In step S003, it is determined whether the facing surface or the document is facing the CIS. One line of data is read by CIS, and a control sequence similar to shading is performed. For example, when determining whether the image is a white surface or an original, the difference between the average value of the white level and the average value of the read data is obtained. If the threshold value is simply determined by 8 bits, the threshold value for white level judgment is initially adjusted between 0 and 255. Alternatively, if the threshold value is determined by default or the like, a slight margin is expected, and if it is less than the margin value, it is determined that the value is not a normal value.

  For example, assuming that the MAX level of white is 255 and the default value is 200, a slight margin (for example, 10%) is expected, and if the margin value is less than that, it is not a normal value (ie, the original surface is It can be determined that the camera is shooting. The same applies to the black surface.

  Furthermore, if the light distribution correction is used, it is possible to make a more detailed determination as to whether the document is a document or not by referring to the read data of one line and comparing it with neighboring data. If it is possible to determine that the data for one line is uniform data such that there is not much difference between the left and right dots, it is possible to determine that the reference surface or the sheet passing surface of the shading counter plate is being photographed. The white / black level correction and light distribution correction methods and methods are well known and will not be described in particular.

  [Effects of the embodiment]

  As described above, in the image reading apparatus according to the present embodiment (and an image forming apparatus using the same), when reading an image with the CIS, the shading counter plate is placed on the opposite surface, and shading is performed to maintain the image performance. And get an image.

  In order to read a document with high accuracy, the width of the sheet passing path needs to be as narrow as possible. Further, it is desirable that the position of the facing plate for shading to ensure the image performance is as close as possible to the position through which the document passes. In the present embodiment, the polygonal counter plate is rotated to perform shading. However, during an emergency stop, the polygonal counter plate and the document may stop at an unintended location.

  When the document stops, it is necessary to remove the document. However, if there is a document at the CIS position other than the paper passing sensor, the document is hidden in the cover, and the operator does not know whether the document is present or not. A situation arises. If the shading correction plate is rotated even though there is an original, the original may be pinched, and if it is pinched, the original may be damaged.

  Further, when the sheet is passed, it is not known whether the shading correction plate is at the reference position. Therefore, when copying starts as it is, the document may interfere (collision) with the shading facing plate, and may become the document JAM.

  In the present embodiment, it is possible to prevent damage to the original by checking the original before turning the shading facing plate. Further, by returning the shading correction plate to the reference position at the start of reading, it is possible to prevent the document from becoming JAM.

  [Others]

  The present invention can be implemented for an image reading apparatus such as a scanner, an MFP, a facsimile machine, and a copying machine, and an image forming apparatus.

  In addition, it should be thought that the said embodiment is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a block diagram of an image forming apparatus capable of color printing that includes an image reading apparatus. FIG. 3 is a diagram illustrating a control target connected to an image reading device control unit 303 in an ADF 300. 3 is a diagram illustrating a configuration of a control mechanism of an image reading device control unit 303. FIG. It is a figure which shows the internal structure of ADF300. FIG. 5 is an enlarged view of a “B” portion of FIG. 4. It is sectional drawing of a shading opposing board (hexagonal column). It is a figure which shows the reference position detection mechanism of a shading opposing board (hexagonal column). It is a perspective view of a shading opposing board (hexagonal column). It is the schematic which shows the drive mechanism of a shading opposing board (hexagonal column). It is a flowchart which shows rotation control (initial position return control) of a shading opposing board. It is a flowchart which shows position control of a shading opposing board. It is a flowchart of the normal rotation process of a motor. It is a flowchart of the reverse rotation process of a motor. It is a figure which shows the position of the shading opposing board at the time of document passing. It is a figure which shows the state in which the shading opposing board 331 interferes with a document. It is a flowchart which shows the process which rotates the shading opposing board 331. FIG.

Explanation of symbols

100 Image forming apparatus 200 Scanner 201 CCD
300 ADF
301 CIS
303 Document Reading Device Control Unit 305 ADF Drive Board 309a Paper Feeding Motor 309c CIS Counter Plate (Shading Counter Plate) Drive Motor 311a Paper Feed Transport Sensor 311b Cover Open / Close Detection Sensor 311c Reference Position Detection Sensor 331 Shading Counter Plate (Hexagonal Column)
331a Rotating shaft 331b Sensor light shielding plate 331d, 331e, 331f Surface 333 Cleaning member 335 Guide plate 500 Controller 501 Reading processing unit 505 Image memory 509 Image control unit 511 Non-volatile memory P Document

Claims (12)

Reading means for reading a document;
A polygonal column that is provided facing the reading unit and has at least a reference surface serving as a reference for image correction of the reading unit;
Conveying means for conveying an original between the reading means and the polygonal column;
Rotating means for rotating the polygonal column about an axis intersecting the document conveying direction;
Correction means for reading the image of the reference plane by the reading means and performing a predetermined image correction;
An image reading apparatus comprising: a stopping unit for stopping the rotation when the reading unit reads the data and acquires data outside a predetermined range before the polygonal column is rotated by the rotating unit. . The polygonal column has a guide surface that guides the conveyed document facing the reading unit;
The image reading apparatus according to claim 1, wherein the rotation unit rotates the polygonal column with a rotation axis orthogonal to the document conveyance direction.   The image reading apparatus according to claim 1, wherein the canceling unit performs reading by the reading unit before starting a document reading operation.   The image reading apparatus according to claim 1, further comprising warning means for giving a warning when the rotation is stopped. A mechanism for opening and closing between the polygonal column and the reading means;
The rotation of the polygonal column is started after the polygonal column and the reading unit are opened and closed after the rotation of the polygonal column is stopped by the stopping unit. The image reading apparatus according to any one of the above. Wherein before you feed the document by the conveying means, to return the polygonal to a reference position by said rotation means, the image reading apparatus according to any one of claims 1 to 5.   The image reading apparatus according to claim 1, further comprising a cleaning member that cleans the polygonal column.   The image reading apparatus according to claim 1, wherein at least one of a white reference surface, a black reference surface, and a sheet passing surface is formed on the polygonal column. A second reading means for reading an original surface different from the original surface read by the reading means;
9. The image reading apparatus according to claim 1, wherein the image on both sides of the document is read by one document transport operation by the transport unit. 10.   An image forming apparatus comprising the image reading apparatus according to claim 1. Reading means for reading a document;
A polygonal column that is provided facing the reading unit and has at least a reference surface serving as a reference for image correction of the reading unit;
Conveying means for conveying an original between the reading means and the polygonal column;
A control method for an image reading apparatus, comprising: a correction unit that reads an image of the reference plane by the reading unit and performs predetermined image correction;
A rotation step of rotating the polygonal column about an axis that intersects the document conveyance direction;
An image reading apparatus comprising: a step of stopping the rotation when the reading unit performs reading before the polygonal column is rotated in the rotation step and data outside a predetermined range is acquired. Control method. Reading means for reading a document;
A polygonal column that is provided facing the reading unit and has at least a reference surface serving as a reference for image correction of the reading unit;
Conveying means for conveying an original between the reading means and the polygonal column;
A control program for an image reading apparatus, comprising: a correction unit that reads an image of the reference plane by the reading unit and performs predetermined image correction;
A rotation step of rotating the polygonal column about an axis that intersects the document conveyance direction;
Before rotating the polygonal column in the rotation step, the image is read by the reading unit, and when data outside a predetermined range is acquired, the computer executes a stop step for stopping the rotation. Reader control program.

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