JP6430837B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus including a detectable paper conveyance path that can detect a paper in a paper conveyance path and a non-detectable paper conveyance path that is a paper conveyance path that conveys the paper for printing. .

  In recent years, an image forming apparatus having a so-called double-sided printing function that forms an image on both sides of a sheet has been widely used.

  For example, in Jpn. Pat. Appln. KOKAI Publication No. 2003-26883, when a jam occurs during double-sided printing, the location where the jam occurs is detected, it is determined whether there is a path that can be transported, and the remaining sheets are automatically detected using the transport path that can be transported. An image forming apparatus that discharges paper is disclosed.

JP 2008-52125 A

  However, the above-described image forming apparatus disclosed in Patent Document 1 uses a different conveyance path when discharging a paper sheet related to a jam, so that the paper or the device parts may be damaged or a new jam may occur. There is.

  On the other hand, if a sensor for detecting paper is omitted in a part of the paper transport path that transports paper during printing, the manufacturing cost can be reduced. However, in such a part, paper can be detected. In other words, there is a problem that it is impossible to determine the presence or absence of residual paper after a jam stop.

  In general, in double-sided printing, in order to increase job efficiency, a paper transport plan is executed in which paper is continuously arranged in a print transport path that guides the paper to the image forming position and a reverse transport path that reverses the paper. ing.

  In such a paper conveyance plan, for example, when a paper jam occurs in the vicinity of the image forming position and the operation of the apparatus is stopped, there are many cases where paper is also present in the reverse conveyance path.

  However, in the case of a device that does not have a paper detection sensor in the reverse conveyance path, even if paper remains in the reverse conveyance path, it cannot be detected, and jamming due to residual paper during re-operation after recovery Will occur again.

  Further, the image forming apparatus of Patent Document 1 cannot cope with such a problem.

  The present invention has been made in view of such circumstances, and an object of the present invention is a sheet conveyance path that conveys a sheet for printing, and is a detectable sheet that can detect a sheet in the sheet conveyance path. In an image forming apparatus including a conveyance path and a non-detectable paper conveyance path that cannot be detected, a detection unit provided at a joining position of the non-detectable paper conveyance path and the detectable paper conveyance path, and the detectable paper conveyance path When a paper jam occurs, the determination means for determining whether or not the paper has been removed, and when it is determined that the paper has been removed, the paper in the undetectable paper transport path is detected for a predetermined time. Drive means for driving after removal to convey the paper in the direction of the paper, and when the paper is jammed in the detectable paper transport path, the paper after detection is undetectable by the drive after removal so that the detection part can detect On the transport path Since to carry the paper to the detection unit, the user is to provide an image forming apparatus that can reliably confirm and remove the presence or absence of paper undetectable sheet conveying path.

  An image forming apparatus according to the present invention is a paper transport path for transporting paper for printing, and includes a detectable paper transport path that can detect paper in the paper transport path and a non-detectable paper transport path that cannot be detected. In the image forming apparatus provided with the detection unit provided at the joining position of the undetectable paper conveyance path and the detectable paper conveyance path, and when the paper jam occurs in the detectable paper conveyance path, the paper has been removed. Determining means for determining whether or not and a driving means for performing post-removal driving for transporting the paper in the undetectable paper transport path in the direction of the detection unit for a predetermined time when it is determined that the paper has been removed. The drive means stops the post-removal drive after the detection result of the detection unit or the predetermined time has elapsed.

  The image forming apparatus according to the present invention includes a discharge port through which a sheet is discharged after printing, and the detection unit is provided in the vicinity of the discharge port.

  The image forming apparatus according to the present invention includes a reporting unit that reports that a sheet is present in the undetectable sheet conveyance path based on a detection result of the detection unit during the driving after removal. .

  The image forming apparatus according to the present invention is characterized in that the driving unit is configured to perform the post-removal driving at a speed faster than normal.

  The image forming apparatus according to the present invention includes a time determining unit that determines the predetermined time based on a length of the undetectable sheet conveyance path.

  The image forming apparatus according to the present invention includes a time determining unit that determines the predetermined time based on a paper size.

  The image forming apparatus according to the present invention includes a time determining unit that determines the predetermined time based on a position of the sheet in the undetectable sheet conveyance path.

  In the image forming apparatus according to the present invention, the front and back sides of the paper are reversed in the undetectable paper conveyance path, and the reverse conveyance of the paper is possible. It is provided in the upstream.

  The image forming apparatus according to the present invention is characterized in that the number of the detection units is two, and another detection unit is further provided on the downstream side of the undetectable sheet conveyance path.

  In the image forming apparatus according to the present invention, openings of different sizes are formed in the vicinity of each detection unit so that the inside of the non-detectable paper conveyance path can be seen, and the drive after the removal is based on the size of the paper. And selecting means for selecting any one of the detectors, and the driving means is configured to convey the sheet based on a selection result of the selecting means.

  According to the present invention, when the paper jam occurs in the detectable paper conveyance path, the driving unit performs the driving after the removal so that the detection unit can detect the paper on the non-detectable paper conveyance path. Since the sheet is conveyed to the detection unit, the user can surely confirm and remove the presence or absence of paper in the undetectable paper conveyance path.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic longitudinal sectional view showing a main part configuration of a multifunction machine according to Embodiment 1 of the present invention. FIG. 3 is a functional block diagram illustrating main functions of the multifunction peripheral according to the first embodiment of the present invention. FIG. 3 is a functional block diagram illustrating a main configuration of a control unit in the multifunction machine according to the first embodiment of the present invention. 5 is a flowchart for explaining the post-removal drive in the multifunction machine according to Embodiment 1 of the present invention. It is a schematic longitudinal cross-sectional view which shows the principal part structure of the multifunctional device which concerns on Embodiment 3 of this invention. It is a functional block diagram which shows the principal part structure of the control part in the multifunctional device which concerns on Embodiment 3 of this invention. 7 is a flowchart for explaining the post-removal drive in a multifunction machine according to Embodiment 3 of the present invention.

  Hereinafter, an example in which an image forming apparatus according to an embodiment of the present invention is applied to a so-called multifunction machine having a plurality of functions will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic longitudinal sectional view showing a main part configuration of a multifunction machine according to Embodiment 1 of the present invention. In FIG. 1, reference numeral “1” represents a multi-function machine according to the present invention. The multifunction machine 1 according to the present invention includes a document reading unit 100, an image forming apparatus 200, a post-processing device 300, and a paper stack unit 400.

  The document reading unit 100 has a document table 101 made of transparent glass or the like on the upper surface. A scanner optical system 111 for optically reading a document placed on the document table 101 is disposed below the document table 101.

  The scanner optical system 111 includes an exposure light source 112 for irradiating light on a document placed on the document table 101 and a photoelectric conversion element (CCD) 115 for receiving light reflected by the document. Between the exposure light source 112 and the photoelectric conversion element 115, a plurality of reflecting mirrors 113 for guiding the light reflected by the document to the photoelectric conversion element 115, and the light guided by the reflecting mirror 113, the photoelectric conversion element 115. An imaging lens 114 for forming an image on the top is disposed.

  An analog output signal output from the photoelectric conversion element 115 is converted into a digital signal (original image data), subjected to image processing, and then sent to an LSU (laser scanning unit) 201 provided in the image forming apparatus 200. Is done.

  The image forming apparatus 200 includes an image forming unit 210 for forming (printing) an image on the recording paper P, and a paper feeding / conveying unit for storing the recording paper P and for conveying the recording paper P to the image forming unit 210. 220.

  Further, in the image forming apparatus 200, when a user can look inside the paper feeding / conveying unit 220 and the recording paper P is jammed, a door (not shown) for removing the recording paper P related to the jamming is illustrated. Z). That is, when the jam of the recording paper P occurs and the operation of the multifunction machine 1 is temporarily stopped, the user opens the door and performs the operation of removing the recording paper P related to the jam.

  The image forming unit 210 includes an LSU 201 and a photoconductor 211 on which an electrostatic latent image is formed by irradiating the surface with laser light from the LSU 201.

  The photoconductor 211 has a drum shape that is rotationally driven in the direction of the arrow in the figure. A developing device is provided around the photoconductor 211 along the rotation direction of the photoconductor 211 from the irradiation point of the laser light from the LSU 201. 212, a transfer charger 213, a static eliminator 214, and a main charger 215 are arranged.

  The developing device 212 develops the electrostatic latent image on the surface of the photoconductor 211 exposed by the laser beam into a visible image (toner image) with toner, and the transfer charger 213 converts the toner image on the photoconductor 211 to the recording paper P. The charge remover 214 removes the charge remaining on the photoreceptor 211 after the toner image is transferred, and the main charger 215 sets the surface of the photoreceptor 211 from which the remaining charge is removed to a predetermined potential. Charge. Further, although not shown, a cleaning device is provided between the transfer charger 213 and the static eliminator 214 for removing the toner remaining on the photosensitive member 211 after the transfer of the toner image.

  The LSU 201 is not limited to the original image data read by the original reading unit 100, but based on image information from an external device such as a computer (not shown) connected to the outside, FAX information received by communication or the like. The photosensitive member 211 is irradiated with a laser.

  Accordingly, the multifunction device 1 has a copying function for reading an original image by the original reading unit 100 to form an image on paper, a FAX function for forming an image on paper based on FAX information by communication, etc., and an external device such as a computer. This is a multifunction device having a print function for forming an image on a sheet based on image information.

  The paper feeding / conveying unit 220 stocks the recording paper P and supplies a paper cassette 221 for feeding the recording paper P, and a manual feed tray 222 for feeding the recording paper P from the outside of the image forming apparatus 200. Is provided.

  At the leading end of the paper cassette 221 on the recording paper P feeding side, a feeding roller 223 for feeding the recording paper P contained in the paper cassette 221 and the recording paper P contained therein are surely received one by one. A roller and a sheet separating portion (not shown) made up of a friction sheet member, a reverse roller or the like are arranged so as to be able to feed out.

  In the conveyance path of the recording paper P, a pickup roller 224 for sending out the recording paper P to the image forming position in the image forming unit 210 and a first paper feeding path 225 are provided on the downstream side of the attracting roller 223. It has been.

  On the other hand, a leading roller 226 for feeding the recording paper P on the manual tray 222 and a recording paper P are guided to the image forming position in the image forming unit 210 at the leading end of the manual paper tray 222 on the recording paper P feeding side. For this purpose, a pickup roller 227 for feeding out and a second paper feed path 228 are provided.

  Before the image forming position of the image forming unit 210, the recording paper P fed from the first paper feed path 225 or the second paper feed path 228 is transferred with a toner image transfer position (image) on the photoconductor 211 at a predetermined timing. A registration roller 229 is provided for conveyance to a (formation position).

  The registration roller 229 is either the first paper feed path 225 or the second paper feed path 228 by a pre-registration detection switch (not shown) provided in the first paper feed path 225 and the second paper feed path 228. Is driven to align the toner image on the photosensitive member 211 and the recording paper P based on a detection signal indicating that the recording paper P has passed.

  A fixing roller for fixing the toner image transferred onto the recording paper P by heat on the downstream side of the transfer position where the toner image on the photoreceptor 211 is transferred to the recording paper P in the conveyance path of the recording paper P. 230 is provided.

  Further, on the downstream side of the fixing roller 230 in the transport path of the recording paper P, a paper transport path 231 for transporting the fixed recording paper P and a recording paper P transported through the paper transport path 231 are image-formed. A first paper transport path 233 for guiding the paper to a paper discharge roller 232 for discharging to the outside of the apparatus 200 is provided.

  The recording paper P discharged from the paper discharge roller 232 is discharged through a discharge port W to a first paper discharge unit 234 formed below the document reading unit 100.

  For switching the recording paper P to either the first paper transport path 233 or the paper transport path 236 leading to the post-processing device 300 on the upstream side of the first paper transport path 233 in the transport path of the recording paper P A first switching gate 235 is provided. The first switching gate 235 is rotatably provided with a branch point between the first paper transport path 233 and the paper transport path 236 as a fulcrum. That is, when the first switching gate 235 guides the recording paper P to the first paper transport path 233, the first switching gate 235 rotates in a direction (upward) to close the paper transport path 236 and guides the recording paper P to the paper transport path 236. In this case, the first paper conveyance path 233 is configured to rotate in the direction of closing (downward).

  Further, the paper feeding / conveying unit 220 is provided with a reverse conveyance path 237 along the paper conveyance path 231. The reverse conveyance path 237 is a conveyance path used during double-sided printing in which images are formed on both sides of the recording paper P. In the reverse conveyance path 237, the recording paper P is in a direction opposite to the conveyance direction in the paper conveyance path 231. To the registration roller 229.

  Therefore, the recording paper P to be printed on both sides is formed with an image on one side and transported to the paper transport path 231, and then once guided to the post-processing device 300 through the paper transport path 236, and switched back in the post-processing device 300. Then, the paper passes again through the paper transport path 236 and is transported to the reverse transport path 237.

  Then, the recording paper P conveyed to the reverse conveyance path 237 is conveyed again to the transfer position of the toner image via the registration roller 229, and the toner image is transferred to the surface where the image is not formed. The paper is fixed and sent to the paper conveyance path 231.

  A switching gate 238 is provided at a branch point between the paper transport path 231 and the reverse transport path 237. When the recording paper P is transported to the reverse transport path 237, the paper transport path 231 is closed. And the conveyance of the recording paper P to the paper conveyance path 231 is prevented.

  Further, in the multi-function device 1, the paper transport path for transporting the recording paper P for printing, that is, the path from the vicinity of the registration roller 229 to the vicinity of the switching gate 238 (indicated by a solid line in the figure) includes the path. A paper sensor (not shown) for detecting the presence or absence of the recording paper P is attached. In the path related to the solid line (hereinafter, this path is also referred to as a detectable paper transport path), the recording paper P is transported from the registration roller 229 toward the switching gate 238 as described above.

  On the other hand, even in the paper transport path for transporting the recording paper P for printing, the paper sensor is not installed in the reverse transport path 237 (indicated by a dotted line in the figure) for determining the recording paper P. To reduce manufacturing costs. In the path related to the dotted line (hereinafter, this path is also referred to as an undetectable paper transport path), the recording paper P is transported from the switching gate 238 toward the registration roller 229 as described above.

  Further, the downstream side of the non-detectable paper conveyance path is configured to merge with the upstream side of the detectable paper conveyance path in the vicinity of the registration roller 229. That is, when the recording paper P is transported on the undetectable paper transport path, the front and back sides are reversed and then transported to the image forming position on the detectable paper transport path.

  Further, a paper detection sensor (detection unit) 240 that detects the presence or absence of the recording paper P is provided in the vicinity of the switching gate 238 and at the junction of the detectable paper conveyance path and the non-detectable paper conveyance path. ing. In other words, the paper detection sensor 240 is provided in the vicinity of the discharge port W. The paper detection sensor 240 detects the presence or absence of the recording paper P transported from the paper transport path 231 to the first paper transport path 233, and the presence or absence of the recording paper P transported from the paper transport path 236 to the reverse transport path 237. Is detected.

  The post-processing apparatus 300 guides the recording sheet P conveyed from the sheet conveyance path 236 of the image forming apparatus 200 to an escape path 302 that is a second sheet conveyance path or a staple tray 303 that is a third sheet conveyance path described later. A paper transport path 301 and a paper discharge roller 318 for discharging the recording paper P transported through the paper transport path 301 to the escape path 302 or the staple tray 303 are provided.

  A second switching gate 304 is provided at a branch point between the escape path 302 and the staple tray 303 on the downstream side of the paper transport path 301 in the recording paper P transport direction. The second switching gate 304 is rotatably provided with such a branch point as a fulcrum. When the recording paper P is guided to the escape path 302, the second switching gate 304 is rotated in the direction of closing the staple tray 303, and the staple is formed. When the recording paper P is guided to the tray 303, the recording paper P is rotated in a direction to close the escape path 302.

  The escape path 302 is a transport path for transporting the recording paper P that is not subjected to post-processing such as stapling processing. The escape path 302 is formed so that the transporting portion of the recording paper P is substantially parallel to the document table 101 of the document reading unit 100. The recording sheet P is conveyed to the sheet stacking unit 400.

  On the other hand, the staple tray 303 is a conveyance path for conveying the recording paper P to be subjected to post-processing such as stapling, and is formed below the escape path 302 in substantially parallel to the escape path 302. Similarly, the recording paper P is conveyed to the paper stack unit 400.

  Further, the staple tray 303 is configured so that the recording paper P is stocked and aligned in a substantially horizontal state, and a stapling process is performed on the recording paper P aligned in the horizontal state by a staple unit 308 described later. Has been.

  In the staple tray 303, on the downstream side of the conveyance of the recording paper P, there are a staple unit 308 that performs a stapling process, and a paper discharge roller 309 that discharges the bundle of recording paper P that has been stapled by the staple unit 308. Is provided.

  The paper stack unit 400 stacks the recording paper P that has passed through the post-processing device 300, and includes a first paper stack tray 401 as a second paper discharge unit and a second paper stack tray as a third paper discharge unit. 402.

  On the first paper stack tray 401, the recording paper P discharged from the escape path 302 of the post-processing device 300 through the first paper discharge path 305 is stacked. That is, the recording paper P that has passed through the post-processing device 300 but has not been subjected to post-processing such as stapling is stacked on the first paper stack tray 401.

  On the other hand, the recording paper P discharged from the paper discharge roller 309 via either the escape path 302 or the staple tray 303 of the post-processing device 300 is stacked on the second paper stack tray 402. In other words, the recording paper P that has been subjected to post-processing such as stapling is stacked on the second paper stack tray 402, but the recording paper P that has not been subjected to post-processing such as stapling is also stacked. .

  Further, the second paper stack tray 402 is configured to move up and down according to the loading amount of the recording paper P. In other words, the second paper stack tray 402 is configured to move downward from a predetermined position when the loading amount of the recording paper P increases.

  FIG. 2 is a functional block diagram illustrating main functions of the multifunction machine 1 according to the first embodiment of the present invention. The MFP 1 according to the first embodiment of the present invention further includes a control unit 900, an operation panel 500, a display unit 600, a storage unit 700, and a time measuring unit 800.

  The operation panel 500 is provided via a function button for switching functions such as “facsimile” and “mail” in the multifunction machine 1, a numeric keypad, a start key, a cancel key, an enter key for confirming an accepted instruction, and the document reading unit 100. An “output” key or a “copy” key for forming an image of the read original on the recording paper P is provided.

  The display unit 600 includes, for example, an LCD or an EL (Electroluminescence) panel, and displays an image to be printed on a predetermined recording sheet P via the image forming unit 210. The display unit 600 also displays information to be notified to the user, such as the status of the multifunction machine 1, the status of job processing, the image of the document read by the document reading unit 100, and the operation content of the operation panel 500. .

  The storage unit 700 is configured by a non-volatile storage medium such as a flash memory, EEPROM (registered trademark), HDD, MRAM (magnetoresistance memory), FeRAM (ferroelectric memory), or OUM, for example.

  The timer unit 800 measures the passage of time and notifies the controller 900 of the elapsed time.

  FIG. 3 is a functional block diagram showing the main configuration of the control unit 900 in the multifunction machine 1 according to Embodiment 1 of the present invention. The control unit 900 includes a CPU 901, a ROM 902, a RAM 903, a drive control unit (drive unit) 904, a report unit (report unit) 905, a time determination unit (time determination unit) 906, and a removed determination unit (determination). Means) 907.

  The ROM 902 stores in advance basic data, etc., among various control programs and operation parameters, and the RAM 903 temporarily stores the data and reads it regardless of the storage order, storage position, etc. Is possible. The RAM 903 stores, for example, a program read from the ROM 902, various data generated by executing the program, parameters that change as appropriate during the execution, and the like.

  The CPU 901 loads the control program stored in advance in the ROM 902 onto the RAM 903 and executes it, thereby controlling the various hardware described above and operating the entire apparatus as the multifunction device 1 of the present invention.

  The removal determination unit 907 determines whether the user has removed the recording paper P when the recording paper P is jammed in the detectable paper conveyance path. Such a determination is made based on, for example, the detection result of the paper sensor after the occurrence of a jam.

  The drive control unit 904 drives the paper feed conveyance unit 220 to control the conveyance of the recording paper. That is, the drive control unit 904 controls the conveyance of the recording paper in the detectable paper conveyance path and the non-detectable paper conveyance path.

  For example, the drive control unit 904 controls the driving of the registration roller 229 and adjusts the timing at which the recording paper P fed from the first paper feed path 225 or the second paper feed path 228 is conveyed to the image forming position. When a jam occurs on the detectable paper conveyance path, the conveyance of the recording paper on the detectable paper conveyance path is stopped.

  The drive control unit 904 reversely drives the undetectable sheet conveyance path for a predetermined time based on the determination result of the removed determination unit 907 after a jam occurs in the detectable sheet conveyance path. That is, when it is determined by the removed determination unit 907 that the recording sheet P has been removed, the drive control unit 904 detects the undetectable sheet in the direction opposite to the normal conveyance direction (forward direction) of the recording sheet P. The conveyance path is driven, and the remaining recording sheet in the undetectable sheet conveyance path is conveyed to the sheet detection sensor 240 on the upstream side of the undetectable sheet conveyance path.

  In the following description, when the removed determination unit 907 determines that the recording paper P causing the jam has been removed, the recording paper is in the reverse direction (paper) for a predetermined time in the undetectable paper conveyance path. The operation of the drive control unit 904 that is conveyed in the direction of the detection sensor 240 is referred to as post-removal drive.

  When the recording paper P is detected by the paper detection sensor 240 or when a predetermined time has elapsed, the drive control unit 904 stops the driving after removal.

  The reporting unit 905 reports to the user that the recording sheet P exists on the undetectable sheet transport path. In other words, when the paper detection sensor 240 detects the recording paper by the post-removal drive, the notification unit 905 displays, for example, text indicating that the recording paper P exists on the undetectable paper conveyance path on the display unit 600. .

  The time determination unit 906 determines the time (T) during which the post-removal drive is performed, in other words, the time during which the recording paper P in the undetectable paper transport path will reach the paper detection sensor 240. For example, the time determination unit 906 calculates the time (T) according to the length of the undetectable paper transport path. Moreover, this invention is not restricted to this, You may comprise so that the said time (T) may always be a fixed time.

  FIG. 4 is a flowchart for explaining the post-removal drive in the multifunction machine 1 according to the first embodiment of the present invention. Hereinafter, for convenience of explanation, the case where the detectable paper transport path is a path related to the solid line in FIG. 1 and the non-detectable paper transport path is the path related to the dotted line in FIG. The case where it performs is demonstrated as an example. However, the present invention is not limited to this, and the detectable paper transport path may be, for example, the first paper feed path 225 or the second paper feed path 228.

  The user places a plurality of documents on an automatic document feeder (ADF) (not shown), and operates the operation panel 500 as appropriate to instruct double-sided printing on recording paper.

  At this time, the CPU 901 accepts such an instruction from the user via the operation panel 500 and starts printing (step S101). More specifically, the CPU 901 instructs the document reading unit 100 to read a document, and instructs the image forming apparatus 200 to perform printing based on the document image data read by the document reading unit 100.

  Next, the CPU 901 determines whether or not a jam has occurred based on a signal from a jam sensor (not shown) provided in the paper feeding / conveying unit 220 or the like (step S102). If the CPU 901 determines that a jam has not occurred (step S102: NO), the process returns to step S102, and such determination is repeated. At this time, printing is continued.

  On the other hand, if the CPU 901 determines that a jam has occurred (step S102: YES), the CPU 901 temporarily stops the operation of the own device (step S103). At this time, the user opens the door of the image forming apparatus 200 and performs an operation of removing the recording paper P related to the jam.

  Next, the removal completion determination unit 907 determines whether or not the door has been closed, that is, whether or not the user has finished the operation of removing the recording paper P related to the jam and closed the door (step S104).

  If the removal determination unit 907 determines that the door is not closed (step S104: NO), the process returns to step S103. On the other hand, when it is determined that the door is closed (step S104: YES), the removal completion determination unit 907 determines whether or not the removal of the recording paper P related to the jam has been completed (step S105). Such determination has already been described, and detailed description thereof will be omitted.

  When the removal completion determination unit 907 determines that the recording paper P related to the jam has not been removed (step S105: NO), the process returns to step S103.

  On the other hand, when it is determined by the removal completion determination unit 907 that the recording paper P related to the jam has been removed (step S105: YES), the time determination unit 906 calculates a time (T) to drive after removal. (Step S106), the CPU 901 instructs the timing unit 800 to start timing. The calculation of the time (T) by the time determination unit 906 has already been described, and detailed description thereof will be omitted.

  At this time, the CPU 901 instructs the drive control unit 904 to execute the post-removal drive. In response to the instruction from the CPU 901, the drive control unit 904 starts executing the post-removal drive (step S107).

  Thereafter, the CPU 901 determines whether or not the recording paper is detected by the paper detection sensor 240 based on the detection result of the paper detection sensor 240, that is, a signal from the paper detection sensor 240 (step S108). That is, since the post-removal drive is currently being performed, the recording paper P is transported in the reverse direction on the undetectable paper transport path. Accordingly, the recording paper in the undetectable paper conveyance path is detected by the paper detection sensor 240 by the driving after the removal.

  When the CPU 901 determines that the recording sheet is not detected by the sheet detection sensor 240 (step S108: NO), the CPU 901 determines whether or not the time (T) has elapsed based on the timing result of the timing unit 800. (Step S109).

  If the CPU 901 determines that the time (T) has not elapsed (step S109: NO), the process returns to step S108. Further, when the CPU 901 determines that the time (T) has elapsed (step S109: YES), that is, when the time (T) has elapsed without the recording sheet sensor 240 detecting the recording sheet, the detection is not performed. The drive control unit 904 is instructed to stop the conveyance of the recording paper P in the possible paper conveyance path, that is, the drive after the removal. In response to such an instruction from the CPU 901, the drive control unit 904 stops the post-removal drive (step S110).

  Next, the CPU 901 instructs the image forming apparatus 200 to restart printing, and the image forming apparatus 200 warms up in response to the instruction from the CPU 901 (step S111), and restarts the interrupted printing (step S111). Step S112).

  On the other hand, if it is determined in step S108 that the recording sheet is detected by the sheet detection sensor 240 by the CPU 90 (step S108: YES), the notification unit 905 indicates that the recording sheet P exists in the undetectable sheet conveyance path. Is displayed on the display unit 600 to notify that (step S113). Thus, the user can recognize that the recording paper P still remains in the undetectable paper conveyance path.

  In other words, after the notification, in other words, when the recording sheet is detected by the sheet detection sensor 240, the conveyance of the recording sheet P in the undetectable sheet conveyance path, that is, the driving after the removal is stopped. An instruction is given to the drive control unit 904. In response to such an instruction from the CPU 901, the drive control unit 904 stops the post-removal drive (step S114).

  Next, the CPU 901 temporarily stops the operation of the multifunction machine 1 (step S115). Thereafter, the user opens the door of the image forming apparatus 200 and removes the recording paper P detected by the paper detection sensor 240.

  As described above, since the paper detection sensor 240 is provided in the vicinity of the discharge port W, the user can remove the recording paper P detected by the paper detection sensor 240 through the discharge port W. is there.

  As described above, in the multi-function device 1 according to the first embodiment of the present invention, jamming occurs in other recording paper conveyance paths even for an undetectable paper conveyance path in which the presence or absence of recording paper cannot be confirmed due to its configuration. When this occurs, the presence or absence of a recording sheet in the undetectable sheet conveyance path can be confirmed with certainty. Therefore, it is possible to prevent the recording paper on the undetectable paper conveyance path from jamming when restarting the operation.

(Embodiment 2)
In the first embodiment, when the time determination unit 906 calculates the time (T) to be driven after removal, the time (T) is calculated based on the length of the undetectable paper conveyance path. However, the present invention is not limited to this.

  The time (T) calculation by the time determination unit 906 may be calculated based on the size of the recording paper at that time, for example, or based on the size of the recording paper and the length of the undetectable paper conveyance path. You may comprise as follows. Further, the time (T) may be calculated based on the position of the recording paper in the undetectable paper transport path.

  The present invention is not limited to this. For example, the conveyance speed of the recording paper P in the post-removal drive is set to a speed higher than the normal conveyance speed of the recording paper P or the maximum speed in the own machine, and the time determination unit 906 determines the time ( T) may be calculated.

  In the first embodiment, the case where the sheet detection sensor 240 is provided in the vicinity of the switching gate 238 and provided at the junction of the detectable sheet conveyance path and the undetectable sheet conveyance path has been described as an example. The present invention is not limited to this. For example, the paper detection sensor 240 may be provided in the vicinity of the registration roller 229.

(Embodiment 3)
In the above description, the case where the sheet detection sensor 240 is provided at one junction point of the detectable sheet conveyance path and the undetectable sheet conveyance path has been described as an example. However, in the multi-function device 1 according to the third embodiment, paper detection sensors are provided at two locations.

  FIG. 5 is a schematic longitudinal cross-sectional view showing the main configuration of the multifunction machine 1 according to Embodiment 3 of the present invention. The MFP 1 according to the third embodiment has the same configuration as that of the first embodiment, but further includes a sheet detection sensor 250 described later in addition to the sheet detection sensor 240.

  In the multi-function device 1 according to the third embodiment, a paper detection sensor that detects the presence or absence of the recording paper P in the vicinity of the registration roller 229 and at the junction of the detectable paper conveyance path and the non-detectable paper conveyance path. (Detecting unit) 250 is provided. The paper detection sensor 250 detects the presence or absence of the recording paper P conveyed from the paper cassette 221 through the first paper feed path 225 to the detectable paper conveyance path, and can be detected via the non-detectable paper conveyance path. The presence / absence of the recording paper P conveyed to the paper conveyance path is detected.

  Further, in the multifunction machine 1 according to the third embodiment, a small opening 241 and a large opening 242 are formed in the vicinity of the paper detection sensor 240 and the paper detection sensor 250, respectively. In other words, a small opening 241 and a large opening 242 larger than the small opening 241 are formed on the upstream side and the downstream side of the undetectable paper conveyance path. In the drawing, the case where the small opening 241 and the large opening 242 are rectangular is shown as an example, but it goes without saying that the present invention is not limited to this.

  Therefore, the user can look inside the undetectable sheet conveyance path through the small opening 241 and the large opening 242 and visually check whether the recording sheet P remains in the undetectable sheet conveyance path. Can be confirmed.

  FIG. 6 is a functional block diagram showing the main configuration of the control unit 900 in the multifunction machine 1 according to Embodiment 3 of the present invention. As in the first embodiment, the control unit 900 includes a CPU 901, a ROM 902, a RAM 903, a drive control unit (drive unit) 904, a report unit (report unit) 905, and a time determination unit (time determination unit) 906. , A removal determination unit (determination unit) 907 and a selection unit (selection unit) 908.

  The selection unit 908 selects one of the paper detection sensor 240 and the paper detection sensor 250 based on the size of the recording paper during the driving after removal. Further, the drive control unit 904 drives the non-detectable paper conveyance path in the forward direction or the reverse direction so that the recording paper is conveyed to the paper detection sensor side selected by the selection unit 908, and performs the driving after removal. .

  As the information relating to the size of the recording paper described above, for example, the size detection information of the paper cassette 221 and the size detection information of the manual feed tray 222 are used.

  FIG. 7 is a flowchart for explaining the post-removal drive in the multi function device 1 according to the third embodiment of the present invention. Hereinafter, for convenience of explanation, the case where the detectable paper transport path is a path related to the solid line in FIG. 5 and the non-detectable paper transport path is the path related to the dotted line in FIG. The case where it performs is demonstrated as an example. However, the present invention is not limited to this, and the detectable paper transport path may be, for example, the first paper feed path 225 or the second paper feed path 228.

  The user places a plurality of documents on an automatic document feeder (ADF) (not shown), and operates the operation panel 500 as appropriate to instruct double-sided printing on the recording paper P.

  At this time, the CPU 901 accepts such an instruction from the user via the operation panel 500 and starts printing (step S201).

  Next, the CPU 901 determines whether or not a jam has occurred based on a signal from the jam sensor (step S202). If the CPU 901 determines that a jam has not occurred (step S202: NO), the process returns to step S202, and such determination is repeated. At this time, printing is continued.

  On the other hand, if the CPU 901 determines that a jam has occurred (step S202: YES), the CPU 901 temporarily stops the operation of the own device (step S203). At this time, the user opens the door of the image forming apparatus 200 and performs an operation of removing the recording paper P related to the jam.

  Next, the removal completion determination unit 907 determines whether or not the door has been closed, that is, whether or not the removal of the recording paper P related to the jam has been completed and the door has been closed (step S204).

  If the removal determination unit 907 determines that the door is not closed (step S204: NO), the process returns to step S203. On the other hand, if the removal determination unit 907 determines that the door is closed (step S204: YES), the removal determination unit 907 determines whether the removal of the recording paper P related to the jam has been completed (step S205).

  If the removal determination unit 907 determines that the recording paper P related to the jam has not been removed (step S205: NO), the process returns to step S203.

  On the other hand, when the removal determination unit 907 determines that the recording paper P related to the jam has been removed (step S205: YES), the selection unit 908 selects the paper detection sensor 240 and the paper detection sensor 240 based on the size of the recording paper P. One of the sheet detection sensors 250 is selected (step S206). For example, the selection unit 908 selects the paper detection sensor 250 near the large opening 242 when the current size of the recording paper P is equal to or smaller than the size of the A4 paper, and detects the paper near the small opening 241 when the size is larger than A4. Sensor 240 is selected.

  Thereafter, the drive control unit 904 forwards the undetectable sheet conveyance path in the forward direction or the recording sheet P in the undetectable sheet conveyance path toward the sheet detection sensor selected by the selection unit 908. By driving in the reverse direction, the post-removal drive is performed.

  Moreover, since the process of step S207-step S216 is the same as the process of step S106-step S115 in FIG. 4 of Embodiment 1, detailed description is abbreviate | omitted.

  Since the multi-function device 1 according to Embodiment 3 is configured as described above, if a jam occurs in another recording paper conveyance path, the presence / absence of the recording paper P in the undetectable paper conveyance path is determined. It can be confirmed more reliably.

  That is, in the MFP 1 according to the third embodiment, when the size of the recording paper P is equal to or smaller than the size (threshold) of the A4 paper, the paper detection sensor 250 is selected by the selection unit 908 and the non-detectable paper is selected. The recording paper P remaining in the transport path is transported toward the paper detection sensor 250. Since the large opening 242 is formed in the vicinity of the paper detection sensor 250, even when the size of the recording paper P is small as described above, the user can detect the undetectable paper conveyance path via the large opening 242. The recording paper P remaining in the undetectable paper conveyance path can be confirmed with the naked eye.

  In the above, when the size of the recording paper P is equal to or smaller than the size of the A4 paper, the paper detection sensor 250 near the large opening 242 is selected, and when larger than A4, the paper detection sensor 240 near the small opening 241 is selected. The case of being selected has been described as an example. However, the present invention is not limited to this.

  For example, when the size of the recording paper P is equal to or smaller than the size of A4 paper, the paper detection sensor 240 near the small opening 241 is selected, and when larger than A4, the paper detection sensor 250 near the large opening 242 is selected. It may be configured. In the case of such a configuration, when the recording paper P is large, the recording paper P can be easily removed through the large opening 242.

  The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The drive control unit 904, the notification unit 905, the time determination unit 906, the removed determination unit 907, and the selection unit 908 described above may be configured by hardware logic, or the CPU 901 may execute a predetermined program. May be constructed in software.

  In Embodiment 1 of the present invention, a paper transport path for transporting paper for printing, a detectable paper transport path that can detect paper in the paper transport path and a non-detectable paper transport path that cannot be detected. In the image forming apparatus 1 provided, when a paper jam occurs in the detection units 240 and 250 provided at a joining position of the undetectable paper conveyance path and the detectable paper conveyance path, A determination unit 907 that determines whether or not the paper has been removed, and a removal that transports the paper in the undetectable paper transport path in the direction of the detection units 240 and 250 for a predetermined time when it is determined that the paper has been removed Drive means 904 for performing post-drive, and the drive means 904 stops the post-removal drive after the detection results of the detection units 240 and 250 or after the predetermined time has elapsed.

  According to the present invention, when a paper jam occurs in the detectable paper conveyance path, the drive means performs the post-removal drive so that the detection unit can detect after the removal of the paper related to the paper jam. Then, the sheet on the undetectable sheet conveyance path is conveyed to the detection unit. When the detection unit detects a sheet, or after driving after removal for the predetermined time, the driving unit stops the limit driving.

  Embodiment 2 of the present invention is characterized in that a discharge port W through which paper is discharged after printing is provided, and the detection unit 240 is provided in the vicinity of the discharge port W.

  According to the present invention, since the detection unit is provided in the vicinity of the discharge port, when the driving unit performs the driving after the removal, the sheet on the undetectable sheet conveyance path reaches the vicinity of the discharge port. Be transported.

  In the third embodiment of the present invention, it is provided with notifying means 905 for notifying that there is a sheet in the undetectable sheet conveyance path based on the detection results of the detection units 240 and 250 during the driving after removal. It is characterized by.

  According to the present invention, when a paper jam occurs in the detectable paper conveyance path, after the removal of the paper related to the paper jam, the driving unit performs the driving after the removal. When the detection unit detects a sheet, the notification unit notifies that there is a sheet in the undetectable sheet conveyance path.

  Embodiment 4 of the present invention is characterized in that the drive means 904 is configured to perform the post-removal drive at a speed faster than normal.

  According to the present invention, after the paper jam occurs in the detectable paper conveyance path and the paper related to the paper jam has been removed, the driving unit performs the driving after the removal, but at this time, it is earlier than the normal time. The limited driving is performed at a speed.

  Embodiment 5 of the present invention is characterized by comprising time determining means 906 for determining the predetermined time based on the length of the undetectable paper transport path.

  According to the present invention, when a paper jam occurs in the detectable paper conveyance path, the time for the driving means to drive after the removal is determined based on the length of the non-detectable paper conveyance path. Determine.

  Embodiment 6 of the present invention is characterized by comprising time determination means 906 for determining the predetermined time based on the paper size.

  According to the present invention, when a paper jam occurs in the detectable paper conveyance path, the time determination means determines the time for the drive means to perform the drive after removal based on the paper size.

  Embodiment 7 of the present invention is characterized by comprising time determining means 906 for determining the predetermined time based on the position of the paper in the undetectable paper transport path.

  According to the present invention, when a paper jam occurs in the detectable paper conveyance path, the time for the driving means to drive after the removal is set to the position of the paper in the non-detectable paper conveyance path. Determine based on.

  In Embodiment 8 of the present invention, in the non-detectable paper transport path, the paper is turned upside down, and the reverse transport of the paper is possible, and the detection unit 240 detects the non-detectable paper transport path. It is provided in the upstream of this.

  According to the present invention, when a paper jam occurs in the detectable paper conveyance path, the driving unit performs the driving after the removal so that the detection unit can detect the paper in the non-detectable paper conveyance path. The sheet is conveyed upstream of the undetectable sheet conveyance path, that is, in the direction opposite to the normal direction.

  Embodiment 9 of the present invention is characterized in that there are two detection units 240 and 250, and another detection unit 250 is further provided on the downstream side of the undetectable sheet conveyance path.

  According to the present invention, one detection unit is provided on the upstream side of the non-detectable paper conveyance path, and the other detection unit is further provided on the downstream side of the non-detectable paper conveyance path.

  In the tenth embodiment of the present invention, openings 241 and 242 of different sizes are formed in the vicinity of the detection units 240 and 250 so that they can look into the undetectable paper conveyance path. And a selection unit 908 that selects one of the detection units 240 and 250 based on the size of the paper, and the driving unit 904 is configured to convey the paper based on the selection result of the selection unit 908. It is characterized by being.

  According to the present invention, when a paper jam occurs in the detectable paper conveyance path, for example, when the size of the current recording paper is equal to or smaller than a threshold value, the selection unit selects a detection unit near a large opening. If it is larger than the threshold value, a detection unit near the small opening is selected. Based on the selection result of the selection means, the drive means performs the post-removal drive and transports the paper toward the selected detection unit.

1 MFP 240 Paper detection sensor 241 Small opening 242 Large opening 250 Paper detection sensor 900 Control unit 901 CPU
904 Drive control unit 905 Notification unit 906 Time determination unit 907 Removed determination unit
908 Selection section P Recording paper W Discharge port

Claims (10)

In an image forming apparatus comprising a sheet conveyance path that conveys a sheet for printing, a detectable sheet conveyance path that can detect a sheet in the sheet conveyance path, and a non-detectable sheet conveyance path that cannot be detected.
A detection unit provided at a joining position of the non-detectable paper transport path and the detectable paper transport path;
A determination unit for determining whether or not the paper has been removed when a paper jam occurs in the detectable paper conveyance path;
Drive means for performing post-removal driving for transporting the paper in the undetectable paper transport path in the direction of the detection unit for a predetermined time when it is determined that the paper has been removed;
The drive unit stops the post- removal drive when the paper is detected by the detection unit during the post-removal drive or after the lapse of the predetermined time. Equipped with an outlet for paper discharge after printing,
The image forming apparatus according to claim 1, wherein the detection unit is provided in the vicinity of the discharge port.   3. The image according to claim 1, further comprising reporting means for reporting that a sheet is present in the undetectable sheet conveyance path based on a detection result of the detection unit during the driving after removal. Forming equipment.   4. The image forming apparatus according to claim 1, wherein the driving unit is configured to perform the driving after the removal at a speed higher than normal. 5.   5. The image forming apparatus according to claim 1, further comprising: a time determining unit that determines the predetermined time based on a length of the undetectable sheet conveyance path.   5. The image forming apparatus according to claim 1, further comprising a time determination unit that determines the predetermined time based on a paper size. 5. The image forming apparatus according to claim 1, further comprising a time determination unit that determines the predetermined time based on a sheet conveyance speed in the undetectable sheet conveyance path. In the non-detectable paper conveyance path, the paper is reversed upside down, and the paper can be reversely conveyed,
The image forming apparatus according to claim 1, wherein the detection unit is provided on an upstream side of the undetectable sheet conveyance path. There are two detection units,
The image forming apparatus according to claim 8, wherein another detection unit is further provided on a downstream side of the non-detectable sheet conveyance path. Openings of different sizes are formed in the vicinity of each detection unit so that the inside of the undetectable paper conveyance path can be seen,
A selection unit that selects one of the detection units based on the size of the paper when driving after the removal;
The image forming apparatus according to claim 9, wherein the driving unit is configured to convey a sheet based on a selection result of the selection unit.

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