JP2009149430A - Sheet carrying device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet carrying device and an image forming device permitting a user to easily and securely remove remaining paper slips and capable of preventing frequent occurrence of jam caused by remaining paper slips on a sheet carrying path. <P>SOLUTION: In the sheet carrying device, paper slip detection sensors 105, 106 are provided in drawing-storing direction end parts of a fixation carrying unit 2, and paper slip detection sensors 107, 108 are provided in drawing-storing direction end parts of an intermediate tray unit. A controller 121 makes the paper slip detection sensors 105-108 perform paper slip detection operation in accordance with storing operation by each drawing unit, and determines whether or not paper slips remain inside each drawing unit based on the detection results. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sheet conveying apparatus provided in an image forming apparatus such as a copying machine, a facsimile machine, a printer, or a complex machine of these. More specifically, the present invention relates to a sheet conveying apparatus and an image forming apparatus provided with a drawer unit in which a sheet conveying path is formed and can be pulled out from the apparatus main body.

  In a conventional image forming apparatus, a sheet feeding unit that feeds a sheet, an image forming unit that forms an image on a sheet, a sheet conveyance unit that conveys an image-formed sheet downstream, and an image-formed sheet It is common to have a sheet discharge section for discharging the sheet.

  Here, the sheet conveyance unit includes, for example, a sheet conveyance path formed from the image forming unit to the sheet discharge unit, and a conveyance roller that conveys the image-formed sheet along the sheet conveyance path. In addition, as the sheet conveying unit, a reversing mechanism for inverting the image forming surface of the sheet, a reconveying mechanism for conveying an image-formed sheet again to the image forming unit in order to form an image on both sides of the sheet, etc. Some are equipped with.

  In recent image forming apparatuses, there is a configuration in which a sheet conveyance unit is configured as a unit (hereinafter referred to as a “drawer unit”) that can be pulled out from the apparatus main body. With this configuration, workability and operability are improved during jam processing and the like, and a space in the image forming apparatus for jam processing is not required. Further, an increase in the degree of freedom of the apparatus layout has led to an advantage that it contributes to downsizing of the entire image forming apparatus.

  Here, in the case of the configuration having the drawer unit, there is a sheet delivery section that delivers the image-formed sheet between the conveyance path between the drawer unit and the apparatus main body and between the drawer units. Then, when a jam or the like occurs in a state where the sheet stops over the sheet delivery unit, and the drawer unit is pulled out for jam processing, the sheet is caught at the sheet delivery unit and the sheet is torn. There was a problem such as. In such a case, a part of the torn sheet (hereinafter referred to as “the remaining piece of paper”) often remains on the sheet delivery unit.

Therefore, even when the drawer unit is pulled out, even if the sheet is in the state where it is straddled, there is a technology that prevents the sheet from being torn by providing an inclined guide on the front side of the main body so that the sheet is not caught by the drawer operation. It has been proposed (see, for example, Patent Document 1).
JP 2001-261189 A

  However, in the invention described in Patent Document 1, if the catching length of the sheet straddling the sheet delivery section is larger than the inclined guide length, the sheet may be caught and cause sheet breakage that may cause a remaining piece of paper. Therefore, when a jam occurs with the sheet straddling the sheet delivery unit, it has not been possible to completely avoid the occurrence of a remaining piece of paper in the sheet delivery unit due to the drawing operation.

  The remaining piece of paper often occurs in a narrow gap in the conveyance guide that forms the sheet conveyance path, and is difficult for the user to find. In addition, since the sensor for detecting the occurrence of a jam is often provided at one place in the width direction of the sheet conveyance path in order to detect only the sheet passing timing, there are many cases where the apparatus cannot detect the remaining small piece of paper.

  For this reason, even if there is a remaining piece of paper in the sheet conveyance path, it is not detected by the user, and the apparatus cannot detect an abnormality. Therefore, a serious problem occurs that jamming frequently occurs and normal image forming processing cannot be restored. There was a case.

  Therefore, the present invention provides a sheet conveying apparatus and an image forming apparatus that allow a user to easily and reliably remove a remaining piece of paper and prevent frequent occurrence of a jam due to the remaining piece of paper in a sheet conveying path. For the purpose.

  In order to achieve the above object, the sheet conveying apparatus according to the present invention is provided so as to be able to be pulled out and stored in the apparatus main body, and can be pulled out and stored in the apparatus main body, and a first drawer unit that conveys the sheet A second drawer unit that receives and conveys a sheet from the first drawer unit; and while the first drawer unit is moving in the drawer / storage direction, The first foreign matter detection means provided at a position where foreign matter can be detected and the foreign matter in the first drawer unit are detected while the second drawer unit is moving in the drawer / storage direction. A second foreign matter detection means provided at a position where the first and second drawer units are retracted, and the first and second foreign matter detection means. Control means for performing a detection operation and determining whether or not there is a foreign substance in the first and second drawer units based on the detection results of the first and second foreign substance detection means. And

  The sheet conveying apparatus according to the present invention is provided so as to be able to be pulled out and stored with respect to the apparatus main body, and the apparatus includes the drawer unit that conveys the sheet and the drawer unit is moved in the pulling and storing direction. Foreign matter detection means provided at a position where foreign matter inside the main body can be detected, and causing the foreign matter detection means to perform a detection operation during the storing operation of the drawer unit, and based on the detection result of the foreign matter detection means, And control means for determining whether or not there is a foreign substance inside the apparatus main body.

  An image forming apparatus according to the present invention includes an image forming unit that forms an image on a sheet, and the sheet conveying apparatus.

  According to the present invention, it is possible to provide an image forming apparatus in which a user can easily and surely remove foreign matters (such as a remaining piece of paper) and can prevent frequent occurrence of jams due to foreign matters in a sheet conveyance path. Can do.

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

(Description of image forming apparatus)
FIG. 1 is a schematic cross-sectional view showing the overall configuration of the image forming apparatus 1. The image forming apparatus 1 is a copying machine including an electrophotographic image forming process, and includes a fixing conveyance unit 2 and an intermediate tray unit 3. The fixing conveyance unit 2 and the intermediate tray unit 3 are drawer units that can be pulled out from the inside of the image forming apparatus 1 in order to facilitate jamming and the like, and are provided at positions adjacent to each other. Yes.

  In the fixing conveyance unit 2, a registration roller pair 8, a transfer charger 10, a separation charger 11, a conveyance belt 12, a fixing roller pair 13, and a sheet for conveying the respective sheets in this order. A sheet conveyance path (not shown) is arranged. A relay discharge roller pair 15 for discharging the sheet that has passed through the fixing roller pair 13 to the outside of the unit is disposed on the most downstream side in the fixing conveyance unit 2. A unit side sheet path 30 is disposed between the fixing roller pair 13 and the relay discharge roller pair 15.

  The intermediate tray unit 3 can reverse the image surface of the sheet that has passed through the fixing roller pair 13 of the fixing conveyance unit 2 and return it to the unit side sheet path 30 of the fixing conveyance unit 2. The intermediate tray unit 3 can also re-feed the sheet that has passed through the fixing roller pair 13 of the fixing conveyance unit 2 to the registration roller pair 8 of the fixing conveyance unit 2 in order to form a double-sided image.

  The image forming apparatus 1 includes a photosensitive drum 9, a main body side sheet path 31, a discharge roller pair 40, a release cover 41 to which a roller 40 b above the discharge roller pair 40 is attached, and a controller 121 (not shown) that controls the entire apparatus. , Each is arranged. In addition, front loading type feeding cassettes 4, 5, 6, and 7 are attached to the image forming apparatus 1 so as to be able to be pulled out and stored. The fixing and conveying unit 2 and the intermediate tray unit 3 are similar to the feeding cassettes 4, 5, 6, and 7, respectively, on the front side of the image forming apparatus 1, that is, in the direction perpendicular to the sheet surface and the sheet conveying direction ( It can be pulled out (toward the front side in FIG. 1).

  Hereinafter, the flow of sheets in the image forming apparatus 1 will be described. In the image forming apparatus 1, the sheets stacked and stored in any of the feeding cassettes 4 to 7 are fed one by one to the fixing conveyance unit 2. When the fed sheet reaches the registration roller pair 8 whose rotation is stopped through a sheet conveyance path (not shown), a predetermined loop is formed to correct the skew state.

  The registration roller pair 8 starts to rotate at the timing of aligning the position of the toner image on the photosensitive drum 9 rotating in the clockwise direction in FIG. Then, the sheet whose skew state has been corrected is sent to a transfer portion between the photosensitive drum 9 and the transfer charger 10. While the sheet passes through the transfer portion, the toner image on the photosensitive drum 9 is sequentially transferred onto the sheet surface by the transfer charger 10.

  The sheet on which the toner image has been transferred is separated from the photosensitive drum 9 by the separation charger 11 and sent to the fixing roller pair 13 by the conveyance belt 12. While the sheet passes through the nip of the fixing roller pair 13, the toner image on the sheet is fixed on the sheet surface by being heated by the fixing roller 13A and being pressed by the pressure roller 13B.

  The unit-side sheet path 30 includes a sheet discharge path 14 connected to the relay discharge roller pair 15, a sheet transfer path 18 connected to the intermediate tray unit 3, and a reverse transfer path 17 connected to the relay discharge roller pair 15 from the intermediate tray unit 3 side. Branch to The conveyance direction of the sheet that has passed through the fixing roller pair 13 is switched to one of the paths by the switching member 16.

  Specifically, the switching member 16 is in a state in which the sheet conveyance path 18 is closed and the sheet discharge path 14 is opened when the sheet having undergone the toner image fixing process by the fixing roller pair 13 moves toward the relay discharge roller pair 15. . On the other hand, when the sheet is sent out to the intermediate tray unit 3, the switching member 16 closes the sheet discharge path 14 and opens the sheet conveyance path 18. Further, when the sheet conveyed from the intermediate tray unit 3 moves toward the relay discharge roller pair 15, the switching member 16 moves so as to close the sheet conveyance path 18 and open the reverse conveyance path 17.

  In the face-up discharge mode in which the toner image is fixed by the fixing roller pair 13 in the face-up discharge mode in which the image surface of the sheet is discharged upward, the sheet discharge path 14 connected to the relay discharge roller pair 15 is switched by the switching member 16. Led to. The sheet guided to the sheet discharge path 14 is guided to the main body side sheet path 31 by the relay discharge roller pair 15 and the unit side sheet path 30. The sheet guided to the main body side sheet path 31 is discharged onto a discharge tray 50 provided on the outer surface of the image forming apparatus 1 by a rotating discharge roller pair 40.

  On the other hand, the sheet after the toner image fixing process is guided to the sheet conveyance path 18 by the switching member 16 and sent to the intermediate tray unit 3 in the double-side mode in which image formation is performed on both sides of the sheet. In this case, the sheet is reversed by the reversing mechanism (not shown) arranged in the intermediate tray unit 3 at the front and back of the sheet, that is, the leading end and the trailing end in the conveying direction. The sheet that has been turned upside down in the intermediate tray unit 3 is fed by the refeed roller pair 21 to the registration roller pair 8 for transfer of the toner image onto the second surface.

  In the face-down discharge mode in which the image surface of the sheet is discharged downward, the sheet that has undergone the toner image fixing process is guided to the sheet conveyance path 18 by the switching member 16. The sheet guided to the sheet conveyance path 18 is fed into the intermediate tray unit 3 and then switched back and conveyed in the direction of the fixing conveyance unit 2 by a reverse rotation drive of a reverse roller (not shown) provided in the intermediate tray unit 3. The The switchback conveyed sheet is guided to the reverse conveying path 17 by the switching member 16, guided to the main body side sheet path 31 by the relay discharge roller pair 15 and the unit side sheet path 30, and discharged by the rotating discharge roller pair 40. 50 is discharged.

  FIG. 2 is an external perspective view showing a state in which the fixing conveyance unit 2 and the intermediate tray unit 3 are pulled out. The image forming apparatus 1 is provided with a front cover 61 as a cover member that can be opened and closed on the apparatus main body so as to cover the fixing conveyance unit 2 or the intermediate tray unit 3.

  In the image forming apparatus 1, when a jam occurs in the fixing conveyance unit 2 or the intermediate tray unit 3, the user opens the front cover 61 and performs jam processing. Here, when the jam sheet is stored in the fixing conveyance unit 2 or in the intermediate tray unit 3, the user can perform jam processing without any problem by pulling out the fixing conveyance unit 2 or the intermediate tray unit 3. it can.

  However, when a jam occurs in a state in which the sheet extends from the fixing conveyance unit 2 to the intermediate tray unit 3, the jam sheet may be broken if only one unit is pulled out. Further, when a jam occurs with the sheet straddling the main body side sheet path 31 and the discharge roller pair 40 from the fixing conveyance unit 2, the jam sheet is torn when the fixing conveyance unit 2 is pulled out. When the sheet having such a tear is removed, the sheet may not be completely removed, and a remaining piece of paper may be generated as a foreign matter in the image forming apparatus 1.

  In the present embodiment, such a remaining piece of paper can be detected by performing the remaining piece of paper detection operation as follows.

(Explanation of the remaining piece of paper detection operation)
An example of detection of a remaining piece of paper in a sheet transfer portion between the fixing conveyance unit 2 and the intermediate tray unit 3 will be described with reference to FIGS.

  FIG. 3 is a perspective view of the vicinity of the sheet transfer portion of the intermediate tray unit 3. The paper piece detection sensors 107 and 108 are arranged at the center between the delivery guides 301 and 303 and at positions outside the front side plate 304a and the back side plate 304b constituting the frame of the intermediate tray unit 3. These paper piece detection sensors 107 and 108 are for detecting the remaining paper piece between the delivery guides on the fixing conveyance unit 2 side.

  The paper piece detection sensors 105 and 106 are provided in the fixing conveyance unit 2 (not shown). These paper piece detection sensors 105 and 106 are fixed at a position where the remaining paper pieces in the gap between the delivery guides 301 and 303 can be detected when the intermediate tray unit 3 or the fixing conveyance unit 2 is pulled out or stored. Yes.

  The paper piece detection sensors 105 to 108 are, for example, reflection-type optical sensors, and when there is a paper piece remaining (there is a reflector), the paper piece detection sensors 105 to 108 output a predetermined signal voltage to detect the paper piece remaining in the image forming apparatus 1. Functions as a foreign matter detection means.

  Further, a scale sheet 112 is stuck on the drawer rail 111 of the intermediate tray unit 3. A linear encoder 110 is provided as a first pull-out amount detecting unit for reading the scale sheet 112 on the pull-out rail 111 and detecting the amount of the intermediate tray unit 3 pulled out from the apparatus main body.

  Although not described in the drawings, the scale sheet 113 is also attached to the drawer rail of the fixing conveyance unit 2 as in the intermediate tray unit 3. The linear encoder 114 serving as the second pull-out amount detection unit reads the scale sheet 113 to detect the pull-out amount of the fixing conveyance unit 2.

  FIG. 4 is a control block diagram in the image forming apparatus 1. The controller 121 is a control circuit that controls the overall control of the image forming apparatus 1, and is connected to the linear encoder 110, the paper piece detection sensors 105 to 108, the memory 122, the front cover sensor 123, and the display unit 211.

  The controller 121 accumulates and stores the output signals of the paper piece detection sensors 105 to 108 and the output signal of the linear encoder 110 in the memory 122. Then, when the controller 121 detects the remaining paper piece based on the detection results of the paper piece detection sensors 105 to 108, the controller 121 causes the display unit 211 to display the presence of the remaining paper piece and the position of the paper piece.

  FIG. 5 is a schematic side view of the fixing conveyance unit 2 and the intermediate tray unit 3. The method for detecting the remaining piece of paper between the delivery guides of each unit will be described with reference to FIG. As shown in this figure, the paper piece detection sensors 105 and 106 as the first foreign matter detection means are provided at the end of the fixing conveyance unit 2 in the pull-out / storage direction. Further, the paper piece detection sensors 107 and 108 as the second foreign matter detection means are provided at the end of the intermediate tray unit 3 in the drawer / storage direction. The fixing conveyance unit 2 is provided with a delivery guide 201 as a first sheet conveyance path, and the intermediate tray unit 3 is provided with delivery guides 301 and 301 as second sheet conveyance paths.

  FIG. 5A is a diagram illustrating a state in which both units are accommodated in the image forming apparatus 1. FIG. 5B is a diagram illustrating a state where the fixing conveyance unit 2 is pulled out. FIG. 5C is a diagram illustrating a state in which the fixing conveyance unit 2 is being housed in the direction of the arrow A from the pulled-out state. FIG. 5D is a diagram illustrating a state where the intermediate tray unit 3 is pulled out. FIG. 5E is a diagram illustrating a state in the middle of the middle tray unit 3 being retracted from the state where the intermediate tray unit 3 is pulled out.

  The remaining paper piece detection between the delivery guides 301 and 303 when the fixing conveyance unit 2 is pulled out is performed by the paper piece detection sensor 105. Specifically, as shown in FIG. 5C, along with the operation of storing the fixing conveyance unit 2, the paper piece detection sensor 105 scans in the direction of arrow A to check whether there is any remaining paper piece between the delivery guides 301 and 303. .

  Further, the remaining paper piece detection between the delivery guides 301 and 303 when the intermediate tray unit 3 is pulled out is performed by the paper piece detection sensor 106. Specifically, as shown in FIG. 5 (e), along with the operation of storing the intermediate tray unit 3, the paper piece detection sensor 106 scans in the direction of arrow A to check whether or not there is a paper piece remaining between the delivery guides 301 and 303. .

  On the other hand, the remaining paper piece detection of the delivery guide 201 when the fixing conveyance unit 2 is pulled out is performed by the paper piece detection sensor 107. Specifically, as shown in FIG. 5C, along with the operation of storing the fixing conveyance unit 2, the paper piece detection sensor 107 scans and confirms whether or not the paper guide remains in the delivery guide 201 in the arrow A direction.

  Further, the remaining paper piece detection of the delivery guide 201 when the intermediate tray unit 3 is pulled out is performed by the paper piece detection sensor 108. Specifically, as shown in FIG. 5E, along with the operation of storing the intermediate tray unit 3, the paper piece detection sensor 108 scans and confirms whether or not there is a paper piece remaining in the delivery guide 201 in the direction of arrow A.

  By disposing the paper piece detection sensors 105 to 108 as described above, it is possible to simultaneously detect the remaining paper pieces between the respective delivery guides regardless of the pulled-out state of each unit.

  Hereinafter, a method for detecting the remaining piece of paper will be described in detail. In FIG. 3, the intermediate tray unit 3 is pulled out with the sheet straddling between the fixing conveyance unit 2 and the intermediate tray unit 3 due to the occurrence of a jam. As a result, the paper pieces 101a and 101b are transferred to the delivery guides 301 and 303. It is in a state of being sandwiched between.

  The piece of paper 101 a is in a state where a part of the torn sheet is caught in a hole 302 opened in the guide 301. The piece of paper 101 b is in a state of being caught between the delivery guides 301 and 303 and the back side plate 304 b constituting the frame of the intermediate tray unit 3.

  FIG. 6 is a diagram illustrating a change in output voltage as a result of scanning the delivery guide with the paper piece detection sensor. Based on the scan result of the paper piece detection sensor, the display unit 211 provided in the operation unit of the image forming apparatus 1 displays a screen as shown in FIG. For example, the display unit 211 displays a message 202 that prompts the user to open the front cover 61 and a graphic 203 that indicates the location of the remaining piece of paper, and notifies the user of the position where the remaining piece of paper exists. .

  Here, when the linear encoder 110 reads the scale sheet 112, the controller 121 can detect the drawing amount of the unit, and can detect the remaining position of the paper piece based on the drawing amount.

  Note that the remaining graphics on the display unit 211 may be expressed only by a message including position information and number information of each piece of paper. For example, in the present embodiment, the display unit 211 may simply display a message that “there is one remaining paper piece at the center of the delivery unit and one at the back”.

(Explanation of remaining piece of paper detection processing)
FIG. 8 is a flowchart showing the remaining paper piece detection process. This flowchart is executed by the controller 121. Here, after the image forming apparatus 1 is stopped due to the occurrence of a jam, the user opens the front cover 61 and pulls out the intermediate tray unit 3 to perform jam processing, and then returns the intermediate tray unit 3 to its original position and closes the front cover. A case will be described as an example.

  First, the controller 121 stores the paper piece detection sensor signal corresponding to the linear encoder signal in the memory 122 as paper piece remaining detection information (S801). Here, the memory 122 is a buffer memory that is erased from the oldest when the capacity overflows, and secures at least a capacity for the maximum amount of drawer per drawer unit.

  Next, the controller 121 determines whether or not the front cover 61 is closed based on the output of the front cover sensor 123 (S802). If the front cover 61 is not closed, the process returns to step S801. When the front cover 61 is closed, the controller 121 determines whether there is a remaining piece of paper based on the remaining piece detection information stored in the memory 122 (S803).

  If there is a remaining piece of paper, the controller 121 displays the information shown in FIG. 7 on the display unit 211 of the image forming apparatus 1 without starting the return operation of the image forming apparatus 1 (S804). Then, the controller 121 determines whether or not the front cover 61 has been opened based on the output of the front cover sensor 123 (S805). When the front cover 61 is opened, the controller 121 deletes the remaining piece of paper detection information stored in the memory 122 (S806).

  On the other hand, if it is determined in step S803 that there is no remaining paper piece, the controller 121 deletes the remaining paper piece detection information in the memory 122 (S807), and starts a normal image forming apparatus return operation (S808).

  In this way, the controller 121 causes the paper piece detection sensors 105 to 108 to perform a foreign object detection operation (paper piece detection operation) in accordance with the storing operation of each drawer unit, and whether there is a foreign substance in the drawer unit based on the detection result. Determine if. If the controller 121 determines that there is a foreign matter (paper piece) in both or any of the fixing conveyance unit 2 and the intermediate tray unit 3, the controller 121 does not perform the sheet conveyance operation even after the drawer unit is stored in the apparatus main body. To control.

(Other embodiments)
In another embodiment, an image sensor using a CCD element or the like may be used for the paper piece detection sensors 105 to 108. In this case, the paper piece detection sensors 105 to 108 can capture the periphery including the delivery guides and acquire a wide range of images. Therefore, as shown in FIG. 9, it is preferable that the scale sheet 131 is pasted in the vicinity of the guide and the image including this is taken. Detection of the remaining piece of paper is performed by known image processing such as masking processing based on image information when there is no remaining piece of paper.

  FIG. 10 is an example of the display unit 211 when the remaining paper pieces 101a and 101b in FIG. 9 are detected. The display unit 211 displays a message 212 for prompting the user to open the front cover 61 and a graphic 213 indicating the location of the remaining piece of paper, and notifies the user of the position where the remaining piece of paper exists.

  The display unit 211 displays a paper piece image 214a corresponding to the remaining paper piece 101a and a paper piece image 214b corresponding to the remaining paper piece 101b together with a scale. When there is another remaining paper piece, the display unit 211 displays a scroll bar 215. By moving the scroll bar 215, the user may be notified of the remaining position of the other piece of paper.

  In the above description, paper piece detection in the conveyance path in the image forming apparatus is taken as an example. However, the present invention may be applied to a sheet conveying apparatus such as a finisher, sorter, collator, or stacker that does not have an image forming function. Needless to say.

  By using the image sensor as the paper piece detection sensor in this way, it is possible to notify the user of the shape and position of the remaining piece of paper more accurately, making it easier to find the remaining piece of paper and increasing the accuracy of detecting the remaining piece of paper. it can.

1 is a schematic cross-sectional view showing an overall configuration of an image forming apparatus 1. FIG. 3 is an external perspective view showing a state where the fixing conveyance unit 2 and the intermediate tray unit 3 are pulled out. 4 is a perspective view of the vicinity of a sheet delivery portion of the intermediate tray unit 3. FIG. 2 is a control block diagram in the image forming apparatus 1. FIG. 2 is a schematic side view of a fixing conveyance unit 2 and an intermediate tray unit 3. FIG. It is a figure which shows the change of the output voltage as a result of having scanned the delivery guide with the paper piece detection sensor. It is a figure which shows the display of the display part 211 at the time of paper piece detection. It is a flowchart which shows the detection process of the remaining piece of paper. FIG. 6 is a perspective view of the vicinity of a sheet delivery portion of an intermediate tray unit 3 in another embodiment. It is a figure which shows the display of the display part 211 at the time of paper piece detection in other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Fixing conveyance unit 3 Intermediate tray unit 61 Front cover 101 Paper piece 105 Paper piece detection sensor 106 Paper piece detection sensor 107 Paper piece detection sensor 108 Paper piece detection sensor 110 Linear encoder 114 Linear encoder 121 Controller 122 Memory 123 Front cover sensor 211 Display part

Claims (8)

A first drawer unit that is provided so as to be able to be pulled out and stored with respect to the apparatus main body and conveys a sheet;
A second drawer unit that is provided so as to be able to be pulled out and stored with respect to the apparatus main body, and that receives and conveys a sheet from the first drawer unit;
First foreign matter detection means provided at a position where foreign matter in the second drawer unit can be detected while the first drawer unit is moving in the drawer / storage direction;
Second foreign matter detection means provided at a position where foreign matter in the first drawer unit can be detected while the second drawer unit is moving in the drawer / storage direction;
In the storing operation of the first or second drawer unit, the first and second foreign matter detection means performs a foreign matter detection operation, and based on the detection result of the first and second foreign matter detection means, Control means for determining whether there is a foreign substance in the first and second drawer units;
A sheet conveying apparatus comprising:   When the control means determines that there is a foreign substance in both or either of the first and second drawer units based on the detection results of the first and second foreign substance detection means, 2. The sheet conveying apparatus according to claim 1, wherein the sheet conveying operation is not performed even after the second drawer unit is accommodated in the apparatus main body. A first sheet conveyance path provided in the first drawer unit;
A second sheet conveyance path provided in the second drawer unit,
2. The sheet according to claim 1, wherein the first and second foreign matter detectors detect a foreign matter in a sheet transfer portion between the first sheet transport path and the second sheet transport path. Conveying device. First pull-out amount detection means for detecting the pull-out amount of the first pull-out unit;
Second pull-out amount detection means for detecting the pull-out amount of the second pull-out unit;
Display means for displaying the position of the foreign matter based on the detection results of the first and second withdrawal amount detection means;
The sheet conveying apparatus according to claim 1, further comprising: The foreign object detection means is an image sensor that images a foreign object,
The sheet conveying apparatus according to claim 4, wherein the display unit displays an image of a foreign object captured by the image sensor. A cover member that covers the first and second drawer units and is provided to be opened and closed with respect to the apparatus main body;
Storage means for accumulating output signals of the first and second foreign matter detection means,
The control means stores in the storage means the output signals of the first and second foreign matter detection means from when the cover member is opened until it is closed, and in response to the cover member being closed, 2. The output signals of the first and second foreign matter detection means stored in the storage means are read to determine whether or not there are foreign matters in the first and second drawer units. Sheet transport device. A drawer unit which is provided so as to be able to be pulled out and stored with respect to the apparatus main body and conveys a sheet;
Foreign matter detection means provided at a position where foreign matter inside the apparatus main body can be detected while the drawer unit is moving in the drawer / storage direction;
Control means for causing the foreign matter detection means to perform a detection operation during the storage operation of the drawer unit, and determining whether there is a foreign matter inside the apparatus main body based on a detection result of the foreign matter detection means;
A sheet conveying apparatus comprising: Image forming means for forming an image on a sheet;
An image forming apparatus comprising the sheet conveying device according to claim 1.

Images