Image reading device allows plural kind of scanning methods using image plural reading modules to sequentially acquire white reference data when cover member is closed

An image reading device includes a document conveying device, a first reading module and a control portion. When initial white reference data, that is, an initial value of white reference data, is acquired, the control portion performs white reference data acquisition processing in a plurality of reading modes sequentially, and if it is judged that the white reference data meets a predetermined condition through data judging processing in all the plurality of reading modes, the acquired initial white reference data is set as usable, and if it is judged that the white reference data does not meet the predetermined condition through data judging processing in at least one of the plurality of reading modes, the acquired initial white reference data is set as unusable.

INCORPORATION BY REFERENCE

This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2017-253418 filed on Dec. 28, 2017, the entire contents of which are incorporated herein by reference.

BACKGROUND

The present disclosure relates to an image reading device that is used in digital copiers, image scanners, and the like to scan and read a document, and to an image forming apparatus provided with one.

Some conventional image reading devices incorporated in multifunction peripherals and the like using an electrophotographic process are provided with a document conveying device (automatic document feeder) that sequentially sends a document in sheet form to a document stage (contact glass) to read it, and discharges it from the document stage after reading it. Such an image reading device allows two kinds of reading methods, namely, a sheet-through method in which a reading module fixed at an image reading position reads a document conveyed automatically by the document conveying device, and a fixed-document method in which, while the document on the document stage is replaced one by one with a document presser opened and closed every time a document is read, the reading module is moved to scan and read the document placed on the document stage.

The recent mainstream of the sheet-through method mentioned above is a double side simultaneous reading method in which the obverse side and the reverse side of a double sided document is simultaneously read in one document conveying operation by the document conveying device using different reading modules respectively. The reading module that reads the reverse side of the double sided document is arranged on the document conveying device. The document conveying device is provided with a cover member with which a part of a document conveying passage can be opened for document jam handling.

The image reading device involves various types of processing needed for, for example, initial setting and adjustment of the reading module. The processing includes initial white reference data acquisition processing where a light source in the reading module is turned on to acquire, as initial white reference data, light quantity data of reflected light from a white reference plate arranged to face the reading module.

On the other hand, in one known image reading device adopting the double side simultaneous reading method, with consideration given to the space inside the document conveying device and convenience in cleaning the reading position, the reading module for reading the reverse side of a double sided document is arranged at where the cover member opens and closes. The white reference plate is fitted on the cover member across the document conveying passage, and when the cover member is opened, the reading module and the white reference plate separate from each other.

In the structure described above, when the cover member is open, even if the light source is on normally, the reading module cannot receive the reflected light from the white reference plate, and this causes erroneous detection that the light source is not on or is on abnormally. Or, even if the light source is off, when the cover member is open, the reading module receives external disturbance light, and thus the error may not be detected.

Another known image reading device judges whether an image can be read based on the result of detecting whether the document conveying device is open or closed with respect to the image reading device as well as the intensity of external light sensed by an external light sensing means.

SUMMARY

According to one aspect of the present disclosure, an image reading device includes a document conveying device, a first reading module, and a control portion. The document conveying device has a document conveying passage through which a conveyed document passes, a cover member with which a predetermined section of the document conveying passage can be opened and closed, and a rotatable white reference roller which is arranged in the cover member and which faces the first reading module when the cover member is closed. The first reading module is arranged inside the document conveying device and can read an image of the conveyed document conveyed by the document conveying device. The first reading module is provided with a light source, and a sensor which reads, as an image light, reflected light of light shone from the light source to the conveyed document. The control portion controls the first reading module. The control portion can perform white reference data acquisition processing which involves sequentially performing first open/closed checking processing for judging whether the cover member is open or closed, data acquisition processing for acquiring white reference data with the sensor by rotating the white reference roller and turning on the light source after the cover member is judged to be closed through first open/closed checking processing, second open/closed checking processing for rechecking whether the cover member is open or closed after white reference data is acquired through data acquisition processing, and data judging processing for judging whether the white reference data meets a predetermined condition after the cover member is judged to be closed through second open/closed checking processing. When initial white reference data, that is, an initial value of white reference data, is acquired, the control portion performs white reference data acquisition processing in a plurality of reading modes sequentially, and if it is judged that the white reference data meets the predetermined condition through data judging processing in all the plurality of reading modes, the acquired initial white reference data is set as usable, and if it is judged that the white reference data does not meet the predetermined condition through data judging processing in at least one of the plurality of reading modes, the acquired initial white reference data is set as unusable.

This and other objects of the present disclosure, and the specific benefits obtained according to the present disclosure, will become apparent from the description of embodiments which follows.

DETAILED DESCRIPTION

Hereinafter, with reference to the accompanying drawings, embodiments of the present disclosure will be described.FIG. 1is a schematic configuration diagram of an image forming apparatus100provided with an image reading portion6of the present disclosure. InFIG. 1, the image forming apparatus100(here, a digital multifunction peripheral is shown as an example), when performing copy operation, reads image data of a document and converts it into a image signal in the image reading portion6, which will be described later. On the other hand, in an image forming portion3in the main body of the multifunction peripheral2, a photosensitive drum5rotating in the clockwise direction inFIG. 1is electrostatically charged uniformly by an electrical charging unit4. Then, with a laser beam from an exposure unit (for example, a laser scanning unit)7, an electrostatic latent image based on document image data that has been read in the image reading portion6is formed on the photosensitive drum5. Developer (hereinafter called toner) is attached to the formed electrostatic latent image by a developing unit8to form a toner image. Toner is fed to the developing unit8from a toner container9.

Toward the photosensitive drum5, where a toner image has now been formed as described above, a sheet is conveyed from a sheet feeding mechanism10through a sheet conveying passage11via a registration roller pair12to the image forming portion3. The conveyed sheet passes through a nip portion between the photosensitive drum5and a transfer roller13(an image transfer portion), and thereby the toner image on the surface of the photosensitive drum5is transferred to the sheet. The sheet on which the toner image has been transferred is separated from the photosensitive drum5, and is conveyed to a fixing portion14that has a fixing roller pair14a, where the toner image is fixed on the sheet. The sheet that has passed the fixing portion14is conveyed to a sheet conveying passage15that branches into a plurality of directions. The sheet has its conveying direction switched by path switching mechanisms21and22that have a plurality of path switching guides provided at branch points along the sheet conveying passage15, and is then (or after being conveyed to a reversing conveying passage16and having undergone two-sided copying) discharged to a sheet discharge portion comprising a first discharge tray17aand a second discharge tray17b.

Although not illustrated, a static eliminator that removes residual electric charges on the surface of the photosensitive drum5is provided on the downstream side of a cleaning device18in the rotating direction of the photosensitive drum5. The sheet feeding mechanism10includes a plurality of sheet feeding cassettes10aand10bthat are removably fitted to the main body of the multifunction peripheral2to store sheets and a stack bypass (manual feed tray)10cprovided over them. The sheet feeding cassettes10aand10band the stack bypass10care connected, through the sheet conveying passage11, to the image forming portion3formed by the photosensitive drum5, the developing unit8, and the like.

In an upper part of the main body of the multifunction peripheral2, the image reading portion6is arranged, and on the top face of the multifunction peripheral2, a document conveying device27is provided. The bottom face of the document conveying device27serves as a platen (document presser) that presses and holds a document placed on a contact glass25(seeFIG. 2) of the image reading portion6. On the front face of the image reading portion6, an operating portion80is provided. The operating portion80has a liquid crystal display portion and LEDs to indicate the status of the image forming apparatus100, and to display the status of image formation, the number of copies, and so on. In the operating portion80, there are provided, among others, a start button operated by a user to instruct to start image formation, a stop/clear button used, for example, to stop image formation, and a reset button used to bring the different settings in the image forming apparatus100back to default states.

The sheet conveying passage15, specifically, first branches into two, left and right, paths on the downstream side of the fixing roller pair14a, and one path (the path extending rightward inFIG. 1) communicates with a first discharge tray17a. The other path (the path extending leftward inFIG. 1), via a conveying roller pair19, then branches into two paths, and one path (the path extending leftward inFIG. 1) communicates with the second discharge tray17b. On the other hand, the other path (the path extending downward inFIG. 1) communicates with the reversing conveying passage16.

In the main body of the multifunction peripheral2, there is arranged a control portion (CPU)90that controls the operation of the image forming portion3, the image reading portion6, the document conveying device27, and the like.

FIG. 2is a side sectional view showing the internal structure of the image reading portion6and the document conveying device27that automatically conveys a document to the image reading portion6according to one embodiment of the present disclosure.FIG. 3is a partly enlarged view of the structure inside a cover member31of the document conveying device27. On the top face of the image reading portion6, there is arranged the contact glass25formed by an automatic reading glass25aand a manual placement document glass25b. Between the automatic reading glass25aand the manual placement document glass25b, there is arranged a conveying guide54that scoops up the leading edge of the document conveyed by the document conveying device27.

The cover member31of the document conveying device27is supported so as to be pivotable in the arrow AA′ directions relative to a frame (unillustrated) of the document conveying device27about, as a pivot, a pivot shaft31aat a side of the device (on the left side inFIG. 3). In the cover member31, there is formed a document conveying passage d extending from a document feeding tray29to a document discharge tray32. Along the document conveying passage d, there are provided document conveying members formed by a pick-up roller33, a sheet feeding belt34, a separation roller35, a registration roller pair36, a conveying roller pair37, a discharge roller pair43, and the like, and a reverse side reading module50that reads an image on the reverse side of a document.

Adjacent to the reverse side reading module50, a reverse side reading glass56is arranged. The reverse side reading glass56constitutes a part of the inner wall face of the document conveying passage d. In a position facing the reverse side reading glass56across the document conveying passage d, there is arranged a white reference roller55for shading correction in the reverse side reading module50. The white reference roller55is fitted inside the cover member31so as to be rotatable by a motor (unillustrated). The white reference roller55is arranged, depending on whether the cover member31is open or closed, at a position away from the reverse side reading glass56or at a position facing the reverse side reading glass56.

The document conveying path d is curved so as to reverse while leading from the registration roller pair36to the automatic reading glass25a. In the document conveying path d, there are provided, at adequate places, a plurality of sheet detection sensors (unillustrated) including a sheet feeding sensor and a discharge sensor for detecting the presence or passage of a document.

In the cover member31, an open/closed detection sensor60that detects whether the cover member31is open or closed is arranged. The open/closed detection sensor60is a PI (photointerruptor) sensor provided with a detection portion that has a light emitting portion and a light receiving portion. As shown inFIG. 3, when the cover member31is at a closed position, the open/closed detection sensor60is shielded from light with a light-shielding plate61provided on the cover member31side, and a light reception signal level in the detection portion is in a LOW state. When the cover member31is pivoted in the opening direction (upward) from the state inFIG. 3, the light-shielding plate61retracts upward from the detection portion of the open/closed detection sensor60, and the light reception signal level turns to a HIGH state. When the light reception signal of the open/closed detection sensor60is sent to the control portion90(seeFIG. 1), whether the cover member31is open or closed is detected.

Inside the image reading portion6, an obverse side reading module51is arranged. The obverse side reading module51moves in the sub scanning direction (left-right direction inFIG. 2) and meanwhile reads the image of a document placed on the manual placement document glass25b. The obverse side reading module51, while staying right under the automatic reading glass25a, reads an image on the obverse side of a document conveyed by the document conveying device27. At the bottom of the conveying guide54, there is arranged a white reference plate57for shading correction in the obverse side reading module51.

Next, document conveying operation by a sheet-through method using the document conveying device27will be described. In the sheet-through method, a document comprising a plurality of sheets is set, with the image face up, on the document feeding tray29. Then, when a copy start button in an operating portion80(seeFIG. 1) of the image forming apparatus100is switched on, a lift plate (unillustrated) raised by a lift mechanism (unillustrated) pushes the pick-up roller33up via a document. As a result, the weight of a holder (unillustrated) including the pick-up roller33acts on the lift plate and thereby the top face of the document is pressed against the pick-up roller33with a predetermined pressure (sheet feeding pressure).

Here, the pick-up roller33, the driving roller44a, the driven roller44band the sheet feeding belt34are arranged on an unillustrated holder. The pick-up roller33is coupled to the driving roller44aby an unillustrated gear. When a roller driving motor (unillustrated) rotates the driving roller44a, the sheet feeding belt34that is stretched around the driving roller44aand the driven roller44bis driven to rotate, and the pick-up roller33is also driven to rotate.

From the document that is set on the document feeding tray29, generally a plurality of sheets at the top are fed to the nip portion between the sheet feeding belt34and the separation roller35by the pick-up roller33. Then, the separation roller35separates only the one topmost sheet from the document comprising a plurality of sheets to convey it toward the registration roller pair36. Here, after the leading edge of the document is detected by the sheet feeding sensor, the document is conveyed across a predetermined distance. Then the roller driving motor stops so that the pick-up roller33and the sheet feeding belt34stop being driven to rotate, and thus primary sheet feeding is finished. The primarily fed document, with a sag formed in it, has its leading edge stopped by the nip portion of the registration roller pair36.

When a predetermined time has passed after the completion of primary sheet feeding, secondary sheet feeding is started. That is, with operation of the secondary sheet feeding motor (unillustrated), the registration roller pair36is driven to rotate. The document is conveyed toward the automatic reading glass25aby the registration roller pair36and the conveying roller pair37. The document conveyed to the automatic reading glass25atouches a document holding member53arranged opposite the automatic reading glass25a, and is thereby pressed against the automatic reading glass25afrom above. The image on the obverse side (automatic reading glass25aside) of the document is, through the automatic reading glass25a, read by the obverse side reading module51.

The document that has passed the automatic reading glass25ais, via the conveying guide54, conveyed toward the conveying roller pair37and the discharge roller pair43, and is finally discharged on the document discharge tray32by the discharge roller pair43. At this time, when the discharge sensor detects the passage of the trailing edge of the document, completion of image reading for one document is detected. Here, the discharge sensor has a counting function for counting the number of documents each time conveyance of a document is complete, and if the sheet feeding sensor detects the following document, the conveyance of the second and the subsequent documents is continued in the same way as described above.

When a double sided document is read, the image on the reverse side of the document is read by the reverse side reading module50provided on the upstream side of the document holding member53, and then the image on the obverse side of the document is read by the obverse side reading module51.

FIG. 4is a partly enlarged view of and around the reverse side reading module50and the white reference roller55inFIG. 3. As shown inFIG. 4, the reverse side reading module50is a reading module of a type using a CIS (contact image sensor). Inside the reverse side reading module50, there is provided a light source70, a condenser lens71comprising a plurality of lenses, and a CMOS (complementary MOS) sensor73as a reading means, and the light shone from the light source70and having passed through the reverse side reading glass56is reflected on a document (unillustrated). The reflected light (image light) reflected on the image face passes through the reverse side reading glass56again, is converged by the condenser lens71and is focused on the CMOS sensor73. The focused image light is broken down into pixels in the CMOS sensor73, and is converted into an electric signal reflecting the density of the individual pixels and thus an image is read. The CMOS sensor73is supported on a substrate75.

Although no overlapping description will be repeated here, also the obverse side reading module51(seeFIG. 2) is a reading module of a type using a CIS sensor and has, like the reverse side reading module50, a light source70, a condenser lens71, a CMOS sensor73and a substrate75.

Although in the example under discussion the obverse side reading module51adopts a reading method using a unity-magnification optical system that employs the CMOS sensor73as an image sensor without using a mirror, it is also possible to use a reduction optical system that employs a plurality of mirrors and optical lenses combined with what is called a CCD (charge-coupled device) as an image sensor and that reads a reduced image imaged through the optical lenses.

At various times such as when the image forming apparatus100starts to be supplied with power or recovers from a power saving state (a sleep mode), when there has been a predetermined change in temperature or humidity, and when image reading processing is started, processing needed for initial setting or adjustment of the reverse side reading module50and the obverse side reading module51is performed. The processing includes white reference data acquisition processing where the light source70of the reverse side reading module50or the obverse side reading module51is turned on to acquire white reference data from the white reference roller55or the white reference plate57.

When white reference data acquisition processing in the reverse side reading module50is performed, as shown inFIG. 3, the cover member31is closed and the white reference roller55is arranged to face the reverse side reading glass56. In this state, while the white reference roller55is rotated, the light source70is turned on, so that the light shone from a light source70is reflected on the white reference roller55, and then is converged by the condenser lens71to be led to the CMOS sensor73. The output level of the CMOS sensor73at this time is acquired as light quantity data (white reference data).

More specifically, while the white reference roller55is rotated, the output level of the CMOS sensor73is sensed a plurality of times to acquire a plurality of pieces of light quantity data. Then, extremely low values (abnormal values) are excluded, and an average value of usable pieces of light quantity data is calculated. With this, an influence of abnormal data caused by variation in the state of the surface of the white reference roller55can be reduced. When the calculated average value of the light quantity data is larger than or equal to a reference value, the white reference data is judged to be usable, and when it is smaller than a reference value, the white reference data is judged not to be usable.

Here, if white reference data acquisition processing is performed with the cover member31open, since the white reference roller55is away from the reverse side reading glass56, even if the light source70is on normally, the CMOS sensor73cannot receive the reflected light from the white reference roller55, and this causes erroneous detection that the light source70is not on. Or, even if the light source70is off or is on abnormally, when the cover member31is open, the CMOS sensor73receives external disturbance light, and thus the error may not be detected.

As described above, whether the cover member31is open or closed is detected by detecting whether the optical path of the open/closed detection sensor60provided on the document conveying device27is open or blocked by the light-shielding plate61provided on the cover member31. Here, due to the approaching or separating strokes between the open/closed detection sensor60and the light-shielding plate61when the cover member31is opened or closed, software-based detection processing, and the like, predetermined detection time is required. On the other hand, white reference data acquisition processing in the reverse side reading module50requires shorter checking time because the CMOS sensor73is used. Due to this, a time lag arises between the timing of open/closed detection for the cover member31and the timing of the start of white reference data acquisition processing, sometimes leading to a situation where, although the cover member31has already started to be opened, white reference data acquisition processing is performed on failing to detect that the cover member31is open, and this may lead to erroneous detection of the lighting state of the light source70.

To cope with that, in this embodiment, when white reference data acquisition processing is performed in the reverse side reading module50, after the cover member31is detected to be at a closed position by the open/closed detection sensor60, the light source70is turned on to acquire white reference data. Then, after white reference data acquisition is complete, whether the cover member31is at the closed position is detected again, and when it is confirmed that the cover member31is at the closed position, whether white reference data is larger than or equal to a reference value is checked.

FIG. 5is a flow chart showing an example of control when, in the document conveying device27of this embodiment, white reference data acquisition processing in the reverse side reading module50is performed to acquire initial white reference data, that is, an initial value of white reference data. With reference also toFIGS. 1 to 4as necessary, the procedure for acquiring initial white reference data will be described along the steps inFIG. 5. Acquisition of initial white reference data is performed on the image forming apparatus100in an initial state as when the image forming apparatus100is shipped from a factory or is installed at a site of use.

When acquisition of initial white reference data in the reverse side reading module50is requested (step S1), the control portion90sets a reading mode number n at1(step S2). The reading mode refers to, for example, one or combination of a color mode, a monochrome mode, and modes of different resolutions (600 dpi or 300 dpi). This embodiment deals with four kinds of reading modes, namely, a color mode with a resolution of 600 dpi, a color mode with a resolution of 300 dpi, a monochrome mode with a resolution of 600 dpi, and a monochrome mode with a resolution of 300 dpi. These reading modes are assigned different reading numbers1to4respectively.

Next, the control portion90judges, based on a detection signal sent from the open/closed detection sensor60, whether the cover member31is at the closed position or not (step S3, first open/closed checking processing). If the cover member31is at the open position (No is step S3), a request to close the cover member31is displayed on the liquid crystal display portion in the operating portion80(step S4), and the procedure returns to step S3.

If the cover member31is at the closed position (Yes in step S3), the control portion90starts rotating the white reference roller55(step S4). Then, an n-th reading mode (here, the first one, that is, the color mode with a resolution of 600 dpi) is set (step S6), and the light source70of the reverse side reading module50is turned on to acquire white reference data from the quantity of light that is reflected on the white reference roller55to enter the CMOS sensor73(step S7, data acquisition processing). Specifically, out of 100 pieces of light quantity data obtained by sensing 100 times the light entering the CMOS sensor73, a predetermined number (30) of pieces of data with an extremely low light quantity are excluded, and using the remaining (70) pieces of data, an average value is calculated to be taken as white reference data.

Next, after a predetermined time has passed since the acquisition of white reference data (Yes in step S8), the control portion90judges again, based on a detection signal sent from the open/closed detection sensor60, whether the cover member31is at the closed position (step S9, second open/closed checking processing). If the cover member31is at the open position (No in step S9), the cover member may have been opened during the acquisition of white reference data. Thus, the light source70is turned off and the rotation of the white reference roller55is stopped (step S10); the procedure then returns to step S4to request to close the cover member31, and then returns to step S3to check whether the cover member31is closed, to rotate the white reference roller55, and to acquire white reference data again (steps S3to S7).

In step S9, if the cover member31is at the closed position (Yes in step S9), the control portion90stops rotating the white reference roller55(step S11) and then judges whether the white reference data obtained in step S7meets a prescribed condition, that is, whether the light quantity data is larger than or equal to a reference value (step S12, data judging processing). Then, if the white reference data meets the prescribed condition (Yes in step S12), the control portion90judges whether white reference data has been acquired in all the reading modes (step S13).

If there is any reading mode for which white reference data has not been acquired (No in step S13), the reading mode number n is incremented by one (step S14), and the procedure returns to step S5to repeat white reference data acquisition for the reading modes number2to4(step S5to S13). In step S13, if white reference data for all the reading modes has been acquired (Yes in step S13), the white reference data is set as usable (step S15), and the procedure is finished.

On the other hand, if, in step S12, white reference data does not meet the predetermined condition (No in Step S12), the initial white reference data is set as unusable (step S16), a notification indicating abnormal initial white reference data is displayed on the liquid crystal display portion in the operating portion80(step S17), and the procedure is finished.

As described above, in the image reading portion6of this embodiment, when initial white reference data is acquired in the reverse side reading module50, it is checked whether the cover member31is open or closed before and after the acquisition of white reference data. If the cover member31is open before the acquisition of white reference data, white reference data is not acquired and it is requested to close the cover member31. Also, even if the cover member31is closed before the acquisition of white reference data, if the cover member is open after the acquisition of white reference data, data judging processing is not performed, and it is requested to close the cover member31to acquire white reference data again. Thus, white reference data can be acquired with the cover member31closed reliably and this prevents failure in acquiring white reference data.

By rechecking whether the cover member31is closed after the predetermined time has passed since the acquisition of white reference data, even if a certain length of time is required to detect whether the cover member31is open or closed, the open/closed state of the cover member31can be reliably detected after the acquisition of light quantity data. It is thus possible to more effectively prevent failure in acquiring white reference data.

In the example of control inFIG. 5, after white reference data is acquired (step S7), if the cover member31is not closed (No in step S9), the light source70is turned off. However, it is also possible to configure to request closing of the cover member31with the light source70turned on, and after the cover member31is confirmed to be closed, to acquire white reference data again.

FIG. 6is a flow chart showing an example of control for performing shading correction during the reverse side automatic reading by the reverse side reading module50. With reference also toFIGS. 1 to 5as necessary, the procedure for performing shading correction during the reverse side automatic reading will be described along the steps inFIG. 6.

When reverse side automatic reading of a conveyed document by the reverse side reading module50is requested (step S1), the control portion90requests acquisition of white reference data prior to image reading (step S2). The control portion then checks whether the cover member31is at the closed position (Yes in step S3), and starts to rotate the white reference roller55(step S5). Thereafter, the steps of acquiring white reference data (step S6), rechecking whether the cover member31is closed (step S8), and stopping the rotation of the white reference roller55(step S10) are the same as those in the initial white reference data acquisition procedure shown inFIG. 5.

Next, the control portion90judges whether the white reference data acquired in step S6meets the predetermined condition, that is, whether the light quantity data is larger than or equal to the reference value (step S11). Then, if the white reference data meets the predetermined condition (Yes in step S11), the acquired white reference data is taken (step S12).

On the other hand, if the white reference data does not meet the predetermined condition (No in step S11), it is checked whether the initial white reference data acquired through the procedure shown inFIG. 5is usable (step S13). Then, if the initial white reference data is usable, (Yes in step S13), the acquired white reference data is replaced with the initial white reference data (step S14). On the other hand, if the initial white reference data is not usable (No in step S13), the acquired white reference data is taken (step S12).

Then, image reading by the reverse side reading module50is performed (step S15), and shading correction is performed using the white reference data set in step S12or the initial white reference data after the replacement in step S14(step S16).

According to the example of control inFIG. 6, if the white reference data acquired prior to image reading does not meet a predetermined condition, and in addition initial white reference data is usable, the acquired white reference data is replaced with the initial white reference data to perform shading correction. With this, even if the white reference roller55is soiled or scratched after durability use, it is possible to perform shading correction accurately using initial white reference data. If initial white reference data is unusable, the acquired white reference data is as it is used to perform shading correction, and this prevents failure in image reading resulting from shading correction not being performed.

The embodiment described above is in no way meant to limit the present disclosure, which thus allows for many modifications and variations within the spirit of the present disclosure. For example, although the embodiment described above deals with the image reading device which is composed of the image reading portion6and the document conveying device27, and which has the reverse side reading module50arranged inside the document conveying device27and the obverse side reading module51arranged inside the image reading portion6, the present disclosure is also applicable similarly to image scanners which have only one reading module corresponding to the reverse side reading module50described above and which is used separately from an image forming apparatus100.

The present disclosure is applicable to image reading devices provided with a reading module arranged inside a document conveying device. Based on the present disclosure, it is possible to provide an image reading device which can prevent erroneous detection caused by the cover member being opened or closed during light source lighting check processing in the reading module, as well as an image forming apparatus provided with such an image reading device.