JP2013093770A - Image reading apparatus and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continue image reading even if there is a failure in an intermediate sensor in three sensors arrayed.SOLUTION: An image reading apparatus comprises: a document length sensor S110A, a document presence/absence sensor S109 and an after separation sensor S113 arranged from upstream to downstream in a document conveyance direction, for emitting document detection signals; a panel operation section 105 which displays an operation state of the apparatus; and a CPU 101 which controls operation of a document separation roller 112 to cause the document separation roller to convey a document, and receives the detection signals from the document length sensor, the document presence/absence sensor and the after separation sensor to cause the separation roller to continue to convey the document. Upon receipt of the detection signal from the document length sensor without receiving the detection signal from the document presence/absence sensor, the CPU can cause the document separation roller to convey the document when received the detection signal from the after separation sensor, and displays on the panel operation section that conveyance of the document can be continuously performed even though the document presence/absence sensor is failed.

Description

  The present invention relates to an image reading apparatus including three or more sensors for detecting a document, and an image reading apparatus including the image reading apparatus.

  2. Description of the Related Art Conventionally, there is an image forming apparatus that includes an image reading apparatus in an apparatus main body, reads an original with an image reading apparatus, and copies an image on a sheet based on image reading information. The main body of the image forming apparatus and the image reading apparatus are provided with a plurality of sensors, and can detect the current position of a document or a sheet or a sheet jam (jam) based on an output signal from each sensor.

  However, some sensors may fail. In this case, there is a problem that the image forming apparatus must be stopped until the service person comes to repair.

  An invention that addresses such a problem is disclosed in Patent Document 1. In the image forming apparatus disclosed in Patent Document 1, when the first sensor (precycle end sensor) of the document conveyance path in the image reading apparatus fails, the image forming apparatus switches to a sequence in which the first sensor is not used and continues image reading. It can be done.

JP 2002-139967 A

  In general, a sensor that is likely to fail is an intermediate sensor among a plurality of sensors arranged in the document transport path. Since the intermediate sensor is activated each time the document passes, the intermediate sensor is frequently operated and easily breaks down.

  On the other hand, the pre-cycle end sensor of the conventional image forming apparatus detects the document one sheet before the last document stacked on the document tray, and the operation frequency is higher than that of the intermediate sensor. It is a sensor that is low and less likely to fail than the intermediate sensor.

  Therefore, the advent of an image reading apparatus capable of continuing image reading of a document even if the intermediate sensor having a high failure occurrence rate fails has been awaited.

  The present invention provides an image reading apparatus that can continue image reading even if an intermediate sensor out of three arranged sensors fails, and an image forming apparatus that includes this image reading apparatus and has a high operating rate. There is to do.

  The image reading apparatus of the present invention reads an original conveyed from the original stacking means by the conveying means by the image reading unit, and is arranged in order from upstream to downstream in the original conveying direction, and issues an original detection signal. A first sensor, a second sensor and a third sensor; a status display means for displaying an operating state of the image reading apparatus; and an operation control of the conveying means to cause the conveying means to convey an original, the first sensor, Control means for receiving document detection signals from the second sensor and the third sensor and causing the transport means to continue transporting the document, and the control means receives the document detection signal from the first sensor. Even if the original detection signal from the second sensor is not received, the original can be conveyed to the conveying means when the original detection signal from the third sensor is received. In the second, but sensor is faulty, to indicate that the conveyance of the document can be continued, it is characterized by.

  An image forming apparatus according to the present invention includes the above-described image reading device and an image forming unit that copies a document on a sheet based on image information read by the image reading device.

  Since the image reading apparatus according to the present invention can continue the conveyance of the document even if the second sensor (intermediate sensor) fails, it is not necessary to stop the serviceman until it comes to repair, improving usability. Can be made.

  According to the image forming apparatus of the present invention, even if the second sensor of the image reading apparatus fails, the image reading apparatus can continue to convey the original, so that the operation rate can be increased without stopping the original copying operation. Can be increased.

FIG. 2 is a schematic cross-sectional view of the image forming apparatus according to the embodiment of the present invention along the sheet conveying direction. FIG. 3 is a cross-sectional view of the image reading apparatus according to the embodiment of the present invention along the document conveyance direction. FIG. 3 is a block diagram of a control unit of the image reading apparatus in the first embodiment. 3 is a flowchart for explaining the operation of the image reading apparatus according to the first embodiment. FIG. 5 is a flowchart for explaining the operation following FIG. 4. FIG. 6 is a flowchart for explaining another operation of the image reading apparatus according to the first embodiment. It is a block diagram of the control part of the image reading apparatus in 2nd Embodiment. 10 is a flowchart for explaining the operation of the image reading apparatus according to the second embodiment. FIG. 9 is a flowchart for explaining the operation following FIG. 8. FIG.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention and an image reading apparatus provided in an apparatus main body of the image forming apparatus will be described with reference to the drawings. In addition, the numerical value shown by embodiment is a reference numerical value, and is not a numerical value which limits this invention.

(Image forming device)
FIG. 1 is a schematic cross-sectional view along the sheet conveying direction of an image forming apparatus according to an embodiment of the present invention.

  The image forming apparatus 10 is equipped with an image reading apparatus 200 (300) on the upper part of the apparatus main body 10A. The image reading apparatus 200 (300) will be described later.

  A plurality of sheet cassettes 11 (only one is shown in the figure and the others are omitted) detachably mounted in the lower part of the apparatus main body 10A of the image forming apparatus 10 are stored. The sheet conveyed from the sheet cassette 11 by the conveyance roller 12 is conveyed to the image forming unit 13. On the other hand, image reading information is sent from the image reading apparatus 200 (300) to the laser scanner 20 by an electric signal. The laser scanner 20 irradiates the photosensitive drum 14 with laser light based on the image information, and forms a toner image on the photosensitive drum 14 by electrophotography. The toner image is transferred from the photosensitive drum 14 to the sheet, and the toner image is fixed by the fixing device 15.

  When a toner image is formed on one side of the sheet, the sheet is discharged to the discharge tray 17 by the discharge roller pair 16. When images are formed on both sides of a sheet, the sheet is switchback conveyed by the discharge roller pair 16 and sent to the retransmission path 18. The sheet is reversed and conveyed by switchback conveyance, and is sent to the image forming unit 13 again. The toner image is transferred to the other surface of the sheet by the image forming unit 13, the toner image is fixed by the fixing device 15, and discharged to the discharge tray 17 by the discharge roller pair 16.

  Furthermore, the apparatus main body 10A is configured to feed sheets not only from the sheet cassette 11 but also from the multi-tray 19 by manual feeding by the user.

(Image reading device)
FIG. 2 is a cross-sectional view of the image reading apparatus along the document conveyance direction.

  The image reading apparatus 200 (300) is arranged in the guide path 129 in which a document is transported from upstream to downstream in the document transport direction, and even if an intermediate sensor among the three sensors fails to generate a document detection signal. The image reading can be continued.

  The image reading apparatus includes a plurality of sensors. An embodiment of the invention in which a document length sensor S110, a document presence / absence sensor S109, and a post-separation sensor S113 are taken as three sensors among the plurality of sensors is referred to as a first embodiment. An embodiment of the invention that takes up three sensors, that is, a post-separation sensor S113, a registration sensor S115, and a lead sensor S116, is referred to as a second embodiment. Note that S110 also has a function as a final document detection sensor.

  The first embodiment and the second embodiment are the same except for the control relationship due to the different sensors to be picked up in the configuration of the entire image reading apparatus. For this reason, in the description of the second embodiment, illustration and description of portions common to the first embodiment are also used.

(Image reading apparatus according to the first embodiment)
The configuration will be described.

  The image reading apparatus 200 is mounted on the upper part of the apparatus main body 10 </ b> A of the image forming apparatus 10. The image reading apparatus 200 transmits image information of a document read by the image reading unit 106 to the laser scanner 20 with an electric signal.

  The image reading apparatus 200 generally includes a document reading unit 117 that reads an image of a document, and a document transport unit 118 that transports the document to the document reading unit 117. The document transport unit 118 is an upper part from the arrow AA in FIG. 2 and is provided in the document reading unit 117 so as to be freely opened and closed.

  The document transport unit 118 will be described.

  The document transport unit 118 includes a document stacking tray 120 as a stacking unit on which the document D (FIG. 1) is placed by the user. The document stacking tray 120 includes three document detection sensors S110A, S110B, and S110C that detect the length of the document, and a pair of alignment plates 119 that align the document width (the front alignment plates are not shown in FIG. 2). And are provided. The pair of alignment plates 119 are moved in a direction approaching and separating from each other by the user so as to align the widths of the documents.

  In FIG. 2, the length of the original is a length in the left-right direction (original transport direction, sub-scanning direction), and the width of the original is a length in a direction intersecting the length direction of the original. The length and width of the document D can be detected by the three document detection sensors S110A, S110B, S110C and the pair of alignment plates 119, and the size of the document can be known. The document detection sensor S110A on the downstream side in the document transport direction also serves to detect that the last document has been drawn into the document transport unit 118 from the document stacking tray 120.

  In the claims, at least one of the three document detection sensors S110A, S110B, and S110C is a first sensor that issues a document detection signal, and a stack detection sensor that detects a document stacked on a document stacking tray 120 as a stacking unit. It is.

  A rotation lever 121 is provided at the entrance of the main body 118 </ b> A of the document transport unit 118. The rotation lever 121 is provided with a base end portion (left end portion in FIG. 2) on the rotation center shaft 123 of the double feed prevention roller 122 so as to be able to rotate in the vertical direction. At a position facing the double feed prevention roller 122, a double feed prevention friction plate 125 is fixed to the main body 118A. A document separation roller 112 is rotatably provided by a rotation center shaft 124 at the distal end portion (right end portion in FIG. 2) of the rotation lever 121. The document separation roller 112 is rotated by a belt (not shown) that spans a pulley (not shown) provided on each of the rotation center shaft 124 and the rotation center shaft 123 of the double feed prevention roller 122. The document separation roller 112 is configured to rotate in a direction in which the connected and driven documents are separated one by one and pulled into the document transport unit 118.

  A document presence sensor S109 is provided at the entrance of the main body 118A of the document transport unit 118. In the document presence / absence sensor S109, a flag S109a is rotatably provided. The post-separation sensor S113 is a sensor that detects whether or not there is a document on the conveyance path.

  In the claims, the document presence sensor S109 is a second sensor that issues a document detection signal, and whether or not the document loaded on the document stacking tray 120 is loaded at a position where it is conveyed by the document separation roller 112 as a roller. A document detection sensor for detecting The post-separation sensor S113 is a third sensor that issues a document detection signal in the claims, and detects a document conveyed above the image reading unit 106 between the document presence sensor S109 and an image reading unit 106 described later. It is a conveyance detection sensor to perform.

  A registration sensor S115 and a registration roller pair 115 are sequentially provided downstream of the double feed prevention roller 122.

  A read roller pair 116 is provided downstream of the registration roller pair 115 in the document conveyance direction, a read sensor S116 is provided downstream thereof, and a reading roller 126, a conveyance roller pair 127, and a discharge roller pair 128 are further provided downstream. It is provided in order. The reading roller 126 faces the image reading unit 106. A discharge sensor S128 is provided between the transport roller pair 127 and the discharge roller pair 128 for detecting the position of the original and measuring the normal rotation and reverse timing of the discharge roller pair 128.

  The rollers 112 and 122 and the roller pairs 115, 116, 127, and 128 are provided in a guide path 129 that constitutes a conveying unit and guides the document. A reverse path 130 is provided between the roller pairs 128 and 115.

  The sensors S109, S113, S115, S116, and S128 are also provided in the guide path 129. The document length sensor S110 is provided at the entrance of the guide path 129.

  Further, the cover 134 is provided with a cover opening / closing sensor S114 that detects opening / closing of the cover 134 that covers the guide path 129.

  The document reading unit 117 will be described.

  On the upper part of the main body 117A of the original reading unit, there are a flow reading original platen glass 132 used when the original is read and read, a fixed reading original platen glass 108 used for fixed reading, and a space between both the glasses. And a scooping member 133 for scooping up the document.

  Inside the main body 117A, an image reading unit 106 composed of a reading sensor (not shown) and LEDs is provided. The image reading unit 106 stops under the flow-reading platen glass 132, reads a document passing on the platen glass 132, and acquires image data. Further, the image reading unit 106 moves under the fixed reading platen glass 108, reads a document placed on the fixed reading platen glass 108 by the user, and acquires image data. .

  Furthermore, a panel operation unit 105 is provided as a state display unit for displaying the operating state of the image reading apparatus on the front side outside the main body 117A as viewed from the user.

  A control part is demonstrated.

  FIG. 3 is a block diagram of the control unit.

  A CPU 101 as a control unit controls the entire image reading apparatus, and is connected to each unit of the image reading apparatus by a system bus 100.

  The CPU 101 is connected to the CPU 140 (FIG. 1) that controls the apparatus main body 10A of the image forming apparatus and an external computer terminal device through a communication I / F 104. One of the CPU 101 and the CPU 140 may be incorporated in the other.

  A RAM 102 and a ROM 103 are connected to the CPU 101. A RAM 102 is a work area for the CPU 101 and a temporary storage area for data. The ROM 103 is an area in which a firmware program for driving the image reading apparatus and a boot program for controlling the firmware program are written. The ROM 103 also stores processing procedures shown in FIGS.

  A panel operation unit 105, an image reading unit 106, and an image processing unit 107 are also connected to the CPU 101. The panel operation unit 105 is used by the user to perform various settings of the image reading apparatus, confirm the settings, and perform various displays. The image processing unit 107 processes and processes the image data acquired by the image reading unit 106 based on user settings.

  Further, the CPU 101 is connected to each of the sensors S110, S109, S113, S114, S115, S116, and S128, and is also connected to a transport motor M that rotates each roller or roller pair based on detection signals of these sensors. Yes. A plurality of transport motors M are provided, but the description of the connection relationship between each roller or roller pair and each transport motor M is omitted.

  The CPU 101 starts the transport motor M when the document length sensor S110A is turned on or when the document presence / absence sensor S109 is turned on and the user operates a start instruction on the operation panel. The transport motor M rotates the rollers 112, 122, 126 and the roller pairs 115, 116, 127, 128.

  A flow reading operation will be described.

  4 and 5 are flowcharts for explaining the operation.

  The image reading apparatus 200 has a case where the original is read by flow reading and a case where the original is read by fixed reading. The flow-reading (flow-reading mode) is a method in which the image reading unit 106 is stopped under the flow-reading original platen glass 132 and the original is passed through the flow-reading original platen glass 132 to read the original. . Fixed reading (fixed reading mode) is a method of reading a document by placing the document on the fixed reading platen glass 108 and moving the image reading unit 106 under the fixed reading platen glass.

  The user presses the start button of the panel operation unit 105 (S301). The CPU 101 determines whether the document presence sensor S109 is ON or OFF. If the document presence sensor S109 is ON (ON in S303), the document is loaded on the document stacking tray 120. Since the document is placed on the document stacking tray 120, at least the document length sensor S110A also detects the document, and the CPU 101 determines the size of the document (S305).

  Since the document presence sensor S109 detects the document, the document is placed at a position where the document is pulled into the main body 118A of the document transport unit 118 by the document separation roller 112. That is, the document is received by the stopper 136 and is loaded on the document stacking tray 120. The stopper 136 is rotated in the main body 118A when the rotating lever 121 is rotated in the downward direction so as not to hinder the conveyance of the document. Since the document presence sensor S109 detects the document, the CPU 101 determines that the document is stacked on the document stacking tray 120 and the document is to be read and read, and the document separation roller 112 is lowered onto the document. And the conveyance motor M is rotated.

  The document separation roller 112 rotates and conveys the document at a speed of about 260 mm / s (S307). The document is fed between the double feed prevention roller 122 and the double feed prevention friction plate 125. The double feed prevention roller 122 and the double feed prevention friction plate 125 convey only the uppermost original when two or more originals overlap. The document is sent to the registration sensor S115.

  Thereafter, when the registration sensor S115 detects the leading edge of the document, the CPU 101 stops the rotation of the registration roller pair 115. The registration roller pair 115 receives the leading edge of the document. However, the double feed prevention roller 122 continues to rotate. Therefore, when the document is bent and the document is skewed, the document is straightly corrected. The CPU 101 stops the rotation of the registration roller pair 115 for a predetermined time, and resumes the rotation of the registration roller pair 115 when the skew of the original is corrected. The registration roller pair 115 feeds the document to the read roller pair 116. The read roller pair 116 and the read roller 126 convey the original and send it onto the platen glass 132 for flow reading. Then, the scooping member 133 scoops the leading edge of the document and scoops it up from the reading platen glass 132 and guides it to the conveying roller pair 127. The conveyance roller pair 127 conveys the document to the discharge roller pair 128.

  On the other hand, the image reading unit 106 is stopped below the flow-reading platen glass 132 and reads an image of a document passing on the flow-reading platen glass 132.

  The discharge roller pair 128 discharges the document to the discharge tray 135. As a result, the image formed on one side of the document is read.

  When images are formed on both sides of a document and the images on both sides are read, the CPU 101 temporarily stops rotation of the discharge roller pair 128 from the document discharge rotation direction after a predetermined time after the discharge sensor S128 detects the document, and then reverses the rotation. Let The timing of reverse rotation after the stop is a timing while the trailing edge of the document passes through the guide member 131 and does not come out of the discharge roller pair 128.

  The guide member 131 is pushed away by the document conveyed toward the discharge tray 135 to allow the document to pass therethrough, and the discharge roller pair 128 reversely rotates and guides the document reversely fed to the reversing path 130. It has become.

  The CPU 101 reverses the discharge roller pair 128. The discharge roller pair 128 conveys the document to the reverse path 130. When the document is transported from the guide path 129 to the reversing path 130, the document is switched back and reversed by this switchback transport.

  The CPU 101 temporarily stops the rotation of the registration roller pair 115. Due to the temporary stop of the registration roller pair 115 and the continued rotation of the discharge roller pair 128, the document abutted against the nip of the registration roller pair is bent, and the skew of the document is corrected. Thereafter, the CPU 101 rotates the read roller pair 116, the reading roller 126, and the discharge roller pair 128 to flow the original and pass it over the original platen glass 132, and the image reading unit 106 reads the image on the other side of the original. Make it.

  If the original on which the images on both sides have been read is discharged to the discharge tray 135 as it is, the page order will not be aligned, so that it will be switched back and discharged to the discharge tray 135 again. At this time, the document again passes on the flow reading document table glass 132, but the image reading unit 106 does not perform the image reading operation.

  In this way, the image reading apparatus 200 scans and reads a document, and when there is no stacked document on the document stacking tray 120, the document presence sensor S109 and the document length sensor S110A do not detect the document (OFF in S309). End the document scanning operation.

  The fixed reading operation will be described.

  If the document presence / absence sensor S109 is OFF in processing S303 and the document length sensors S110A, S110B, and S110C are OFF in processing S311, the document is not stacked on the document stacking tray 120 and the start button is pressed. . Therefore, the CPU 101 determines that the image reading apparatus 200 is in the fixed reading mode (S313), and performs fixed reading (S315).

  The operation when the document presence / absence sensor is broken will be described.

  When the user presses the start button in S301, the document presence / absence sensor S109 is OFF (OFF in S303), and at least the document length sensor S110A among the three document length sensors is ON (ON in S311). is there. At that time, since the document length sensor S110A is ON (S311 is ON), the CPU 101 lowers the document separation roller 112 and rotates the transport motor. The document separation roller 112 conveys the document. However, since the document presence / absence sensor S109 is OFF and the document detection signal is not received from the document presence / absence sensor S109, the CPU 101 determines that the document presence / absence sensor is out of order.

  The CPU 101 controls the conveyance motor M to cause the document separation roller 112 to convey the document at a conveyance speed of about 130 mm / s (S331). When the post-separation sensor S113 detects the document (ON in S333), the document separation roller 112 Is temporarily stopped (S335). Then, the CPU 101 displays on the panel operating unit 105 that the document presence / absence sensor S109 has failed but the document can be transported (S337), and further displays an inquiry as to whether or not to transport the document. (S339).

  In the process S337, the panel presence / absence sensor S109 has failed on the panel operation unit 105, but the document is still displayed as being transportable, the process S339 is omitted, and the process proceeds to the process S347. The conveyance may be continued.

  If it is determined in step S339 that the user does not convey the document and the panel operation unit 105 is instructed not to convey the document (NO in S339), the CPU 101 stops the rotation of the document separation roller 112. As a result, the conveyance of the first original (YES in S341) is stopped (S343).

  In the process S333, the post-separation sensor S113 may not detect a document (OFF in S333). In this case, the original cannot be conveyed due to the malfunction of the original presence sensor S109 or the original separation roller 112 not rotating. Therefore, since the post-separation sensor S113 has not detected any document (NO in S341), the CPU 101 instructs the panel operation unit 105 to place the document on the stationary reading platen glass 108 (S345). Thereafter, the user places a document on the stationary reading platen glass 108 and performs fixed reading (S315).

  If it is determined in step S339 that the user can transport the document even if the document presence / absence sensor is faulty, it is determined that the reading operation is continued until the service person replaces the document presence / absence sensor. Input of conveyance of the document to the operation unit is input (YES in S339).

  Thereafter, the CPU 101 detects the size of the document from the document detection signals of the document length sensors S110A, S110B, and S110C and the position of the alignment plate 119 (S347). Thereafter, the CPU 101 controls the conveyance motor M to convey the document at a conveyance speed of about 260 mm / s with each roller and roller pair, and causes the image reading unit 106 to read the document (S349). It should be noted that the document conveyance speed may remain at about 130 mm / s in S331.

  Finally, when the document length sensor no longer detects a document (OFF in S351), the CPU 101 indicates that no document is loaded on the document stacking tray 120, and stops the image reading apparatus.

  In the above description, the reason why the document presence sensor S109 is turned off in step S303 and the document length sensor is turned on in step S311 is that the document presence sensor has failed or the document is not detected by the document presence sensor. One of them.

  Therefore, as shown in FIG. 6, it is assumed that the document is placed on the document stacking tray 120 at a position that is not detected by the document presence / absence sensor, and the panel operation unit 105 displays that the document is set again (S321). May be. The user who sees the display resets the original and presses the start button (S323).

  When the document is set again (S323) and the document presence / absence sensor S109 is turned on (ON in S325), the document presence / absence sensor is not broken, and the CPU 101 proceeds to the process S305 to detect the document. Starts reading. However, if the document presence / absence sensor S109 is not turned on even if the document is set again (OFF in S325), the document presence / absence sensor has failed. Therefore, the CPU 101 reconfirms whether or not the document is detected by the document length sensor by re-mounting the document on the document stacking tray 120 (S327). When the document length sensor S110A detects a document (ON in S327), the process proceeds to S331. When the document length sensor S110A does not detect the document (OFF in S327), the CPU 101 determines that the document is a document of a size that cannot be scanned and moves to S345.

  In this way, the user can quickly reset the original and the image reading apparatus can quickly read the original.

  As described above, the image reading apparatus 200 causes the CPU 101 to rotate the document separation roller 112 when at least the document length sensor S110A of the document length sensor S110A and the document presence / absence sensor S109 detects the document. It has become.

  Further, the CPU 101 may receive a document detection signal from the post-separation sensor S113 without receiving a document detection signal from the document length sensor S110A and receiving a document detection signal from the document presence / absence detection sensor S109. In such a case, the CPU 101 can rotate the document separation roller 112 and displays on the panel operation unit 105 that the document presence / absence sensor S109 has failed but the document can be continuously conveyed. It is like that.

  As a result, even if the document presence / absence sensor S109 breaks down, the user can continue the reading operation of the image reading device until the service person replaces the document presence / absence sensor, thereby improving the operation efficiency of the image reading device. be able to.

  That is, the image reading apparatus according to the present embodiment is characterized in that even if the document presence / absence sensor fails, the functions of the image reading apparatus can be used effectively without making the related portions unusable. I have.

  If the user does not want to continue transporting the document, the image reading apparatus can be stopped and the serviceman can wait until the document presence sensor is replaced.

  Further, when the CPU detects that the document presence / absence sensor is faulty, temporarily stops the conveyance of the document, and displays whether or not to continue the document conveyance on the panel operation unit, the document presence / absence sensor It is possible to confirm the user's intention as to whether or not to transport the document in a failure state.

(Image Reading Device of Second Embodiment)
The image reading apparatus 300 of the second embodiment is as shown in FIG. 2 and has the same structure as the image reading apparatus 200 of the first embodiment.

  However, the CPU 101 (FIG. 3) as the control means for controlling the operation of the image reading apparatus according to the first embodiment moves the document separation roller 112 if at least one of the document presence sensor S109 and the document length sensor S110A is ON. It is designed to rotate. In contrast, the CPU 301 (FIG. 7) serving as a control unit that controls the operation of the image reading apparatus according to the second embodiment is configured so that when both the document presence sensor S109 and the document length sensor S110A are ON, the document separation roller. 112 is rotated.

  Further, the CPU 101 in the control block diagram shown in FIG. 3 of the image reading apparatus of the first embodiment stops the conveyance of the document when the registration sensor S115 fails. However, the CPU 301 in the control block diagram shown in FIG. 7 of the image reading apparatus according to the second embodiment is configured to rotate the registration roller pair 115 and convey the document even if the registration sensor S115 fails.

  Further, the ROM 308 stores the processing procedure shown in FIGS.

  The image reading apparatus 300 according to the second embodiment is as shown in FIG. 2 and has the same structure as the image reading apparatus 200 according to the first embodiment, so that the description of the structure is omitted and the image reading apparatus according to the second embodiment. The operation of 300 will be described.

  FIG. 8 is a flowchart for explaining the operation.

  The image reading apparatus 300 also has a case of reading a document by flow reading and a case of reading by fixed reading.

  The user presses the start button of the panel operation unit 105 (S401). In step S403, the CPU 101 determines whether the document presence sensor S109 has a document placed on the document stacking tray 120.

  When the document presence sensor S109 does not detect a document (OFF in S403), the CPU 301 has no document placed on the document stacking tray 120, and therefore the document is placed on the stationary reading platen glass 108. And shift to the fixed reading mode (S451). The image reading unit 106 performs fixed reading of the original (S452).

  If the document presence / absence sensor S109 detects a document in step S403 (ON in S403), the document is placed on the document stacking tray 120. Thus, at least the document length sensor S110A detects the document, and the CPU 101 determines the size of the document (S405).

  Since the document presence sensor S109 detects the document, the document is placed at a position where the document is pulled into the main body 118A of the document transport unit 118 by the document separation roller 112. That is, the document is received by the stopper 136 and is loaded on the document stacking tray 120. Since the document presence sensor S109 detects the document, the CPU 101 determines that the document is stacked on the document stacking tray 120 and the document is to be read and read, and the document separation roller 112 is lowered onto the document. And the conveyance motor M is rotated.

  Accordingly, the document separation roller 112 rotates and conveys the document at a speed of about 260 mm / s (S407). The document is fed between the double feed prevention roller 122 and the double feed prevention friction plate 125. The double feed prevention roller 122 and the double feed prevention friction plate 125 convey only the uppermost document when two or more documents are overlapped.

  However, when the uppermost original is not detected by the post-separation sensor S113 as the first sensor (OFF in S409), the CPU 301 assumes that the original is jammed or the original separation roller 112 does not rotate (S411), and performs the flow reading. Is terminated or interrupted (S413).

  When the uppermost document is detected by the sensor S113 after separation (ON in S409), the CPU 301 determines whether or not the registration sensor S115 as the second sensor has detected the document (S415). When the registration sensor S115 detects a document (ON in S415), the CPU 301 determines whether the lead sensor S116 as the third sensor has detected a document (S417). When the read sensor S116 detects a document (ON in S417), the CPU 301 continues control of document scanning. Then, the image reading apparatus continues reading until the final document (YES in S419, S413).

  In step S417, when the read sensor S116 does not detect a document (OFF in S417), the CPU 301 stops the operation of the image reading apparatus on the assumption that a document jam (S421) has occurred upstream of the read sensor S116 (S413). .

  In the process S415, the registration sensor S115 may remain OFF for a predetermined time, and the lead sensor S116 may remain OFF after the predetermined time (OFF at S415, YES at S431, OFF at S433). In such a case, the CPU 301 determines that the document is jammed upstream of the registration sensor S115 (S411), and stops conveying the document (S413).

  However, in step S415, the registration sensor S115 may remain off for a predetermined time, and the lead sensor S116 may be turned on after a predetermined time (OFF at S415, YES at S431, and ON at S433). In such a case, the CPU 301 determines that the document sensor cannot be detected due to the failure of the registration sensor S115.

  The registration roller pair 115 rotates before the document reaches the upstream registration sensor S115. When the registration sensor S115 detects the document, the registration roller pair 115 temporarily stops rotating and receives the leading edge of the document. It is designed to straighten the skew. Thereafter, the registration roller pair 115 conveys a document in which skew feeding is straightened.

  However, since the document is not detected when the registration sensor S115 fails, the registration roller pair 115 conveys the document to the read sensor S116 without stopping the rotation and correcting the skew of the document.

  Therefore, when the registration sensor S115 continues to be OFF for a predetermined time in the process S415, and the read sensor S116 as the reading sensor is turned ON after the predetermined time, the registration sensor S115 is broken.

  If the CPU 301 determines in step S433 that the registration sensor S115 has failed, the CPU 301 temporarily stops the document conveyance by the image reading apparatus (S435). Then, the CPU 101 displays on the panel operation unit 105 that the registration sensor S115 has failed but the document can be transported (S437), and further displays an inquiry as to whether or not to transport the document (S437). S439).

  When the user determines that the document is not transported and inputs that the document is not transported to panel operation unit 105 (NO in S439), CPU 101 stops transporting the first document (S413). The user determines that the document is to be transported, and inputs that the document is transported to panel operation unit 105 (YES in S439). Then, the CPU 101 controls the image reading apparatus 300 so as to continue the flow reading at a document conveyance speed of about 130 mm / s until the last document (S441, S500, S413).

  In step S437, it is displayed on the panel operation unit 105 that the document presence / absence sensor S109 is out of order, the document is still displayed as being transportable, step S439 is omitted, and the process proceeds to step S441. The conveyance of the document may be continued (S500).

  The flow reading process (S500) of FIG. 8 will be described based on FIG. 8 will be described only for the relationship between the post-separation sensor S113 and the registration sensor S115, and the description for the relationship with other mechanisms will be omitted.

The original document conveyed in step S441 in FIG. 8 is the first sheet (S501, n = 1).
Following the first document, the second document (S503, n + 1 = 2) is detected by the post-separation sensor S113. The CPU 301 determines whether or not the first (n = 1) document has passed through the registration sensor S115. If the document has been removed (S505, YES), whether or not the subsequent second document is the final document. Is determined (S507). If it is the final document, when the second document is read (S509), the flow reading is terminated (S413).

  If it is determined in step S507 that the second document is not the final document, the third document is read (S511, 3 = 2 + 1). If the third document is the final document, scanning is terminated. If the third document is not the final document, the fourth document is scanned and read. In this way, the continuous reading is continued until the final document.

  In process S505, when the first original does not pass through the registration sensor S115 (NO in S505), the subsequent second original is stopped (S513). When the first original passes through the registration sensor S115 (S515), the conveyance of the subsequent second original is resumed (S517). When the registration sensor is out of order, the conveyance speed of the original at the registration sensor is about 130 mm / s, which is slower than the normal conveyance speed of about 260 mm / s, so that the subsequent original catches up with the preceding original, and the original There is a risk of clogging. For this reason, the conveyance speed of the subsequent original is adjusted.

  As described above, the CPU 301 may receive the document detection signal from the read sensor S116 even if it receives the document detection signal from the sensor S113 after separation and does not receive the document detection signal from the registration sensor S115. . In such a case, the CPU 301 can convey the document without stopping the rotation of the registration roller pair, and the panel operation unit 105 continues to convey the document even though the registration sensor has failed. It is displayed that it is possible.

  As a result, even if the document presence / absence sensor S109 breaks down, the user can continue the reading operation of the image reading device until the service person replaces the document presence / absence sensor, thereby improving the operation efficiency of the image reading device. be able to.

  That is, the image reading apparatus according to the present embodiment is characterized in that even if the document presence / absence sensor fails, the functions of the image reading apparatus can be used effectively without making the related portions unusable. I have.

  If the user does not want to continue transporting the document, the image reading apparatus can be stopped and the serviceman can wait until the document presence sensor is replaced.

  Further, when the CPU detects that the registration sensor has failed, temporarily stops the conveyance of the document, and displays whether or not to continue the conveyance of the document on the panel operation unit, the document presence sensor fails. It is possible to confirm the user's intention as to whether or not to carry the document in the state.

  Further, since the image reading apparatus can continue the conveyance of the original even if the original detection sensor or the registration sensor of the image reading apparatus breaks down, the operation rate is maintained without stopping the original copying operation. Can be increased.

M: conveying motor, 10: image forming apparatus, 10A: image forming apparatus main body, 13: image forming unit, 101: CPU (control unit), 105: panel operation unit (status display unit), 106: image reading unit, 108 : Document platen glass for fixed reading, S109: Document presence sensor (second sensor, document detection sensor), S110A: Document length sensor (first sensor, stacking detection sensor), 112: Document separation roller (conveying means, roller) , S113: Post-separation sensor (third sensor, first sensor, conveyance detection sensor), 115: Registration roller pair (conveyance means), S115: Registration sensor (second sensor, conveyance detection sensor), 116: Pair of read rollers ( (Conveying means), S116: read sensor (third sensor, reading sensor), 117: original reading unit, 118: original conveying unit, 118A: main body, 20: Document stacking tray (stacking means), 122: Double feed prevention roller (conveyance means), 127: Conveyance roller pair (conveyance means), 128: Discharge roller pair (conveyance means), S128: Discharge sensor, 129: Guide path , 130: reverse path, 132: platen glass for flow reading, 134: cover, 136: stopper, 200: image reading device, 300: image reading device, 301: CPU (control means).

Claims (7)

In an image reading apparatus that reads an original conveyed from an original stacking means by a conveying means with an image reading unit,
A first sensor, a second sensor, and a third sensor, which are arranged in order from the upstream to the downstream in the document transport direction and generate a document detection signal;
Status display means for displaying the operating status of the image reading device;
The conveying means is controlled to cause the conveying means to convey the original, and upon receipt of original detection signals from the first sensor, the second sensor, and the third sensor, the conveying means continues to convey the original. Control means,
The control means receives the document detection signal from the first sensor and receives the document detection signal from the third sensor without receiving the document detection signal from the second sensor. The state display means displays that the second sensor is out of order but can continue to transport the document.
An image reading apparatus. The control means displays on the status display means that the second sensor is out of order, but can continue the document transport, and also displays an inquiry as to whether or not to continue the document transport. ,
The image reading apparatus according to claim 1. The transport means includes a roller for transporting a document stacked on the stacking means;
The first sensor is a stacking detection sensor for detecting a document stacked on the stacking means;
The second sensor is a document detection sensor that detects whether or not the document stacked on the stacking unit is stacked at a position conveyed by the roller;
The third sensor is a conveyance detection sensor that detects a document conveyed to the image reading unit between the document detection sensor and the image reading unit;
The roller is adapted to rotate by the control means when at least the stack detection sensor of the stack detection sensor and the document detection sensor detects a document.
The control means receives the document detection signal from the stack detection sensor and rotates the roller when receiving the document detection signal from the transport detection sensor without receiving the document detection signal from the document detection sensor. And the status display means displays the inquiry as to whether or not the document detection sensor is broken but the document transport can be continued and the document transport is continued.
The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus. The control means makes the document conveyance speed of the roller when the document detection sensor is malfunctioning slower than the document conveyance speed when the document detection sensor is normal,
The image reading apparatus according to claim 3. The conveying means includes a registration roller pair that temporarily receives and corrects the skew of the original in a state where the leading end of the original to be conveyed is stopped, and rotates to convey the original.
The first sensor is a conveyance detection sensor for detecting a document upstream of the registration roller pair;
The second sensor is a registration sensor that detects a document between the conveyance detection sensor and the pair of registration rollers;
The third sensor is a reading sensor that detects a document between the pair of registration rollers and the image reading unit;
The registration roller pair is adapted to stop rotation by the control means that has received the document detection signal of the registration sensor,
The control means receives the document detection signal from the conveyance detection sensor, and receives the document detection signal from the reading sensor without receiving the document detection signal from the registration sensor. The document can be transported once without stopping rotation, and the status display means that the registration sensor is out of order but the transport of the document can be continued.
The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus. The control means makes the document conveying speed of the conveying means when the registration sensor is malfunctioning slower than the document conveying speed when the registration sensor is normal;
The image reading apparatus according to claim 5. The image reading apparatus according to any one of claims 1 to 6,
An image forming unit that copies a document on a sheet based on image information read by the image reading device;
An image forming apparatus.

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