JP2006103829A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device capable of facilitating a jam removing method when paper feeding delay/jam occurs and having high usability and to provide a control method for improving usability of the image forming device. <P>SOLUTION: This image forming device is provided with a paper feeding device having a sheet loading tray 110 for loading a plurality of sheets. The paper feeding device has a sheet loading tray mounting and dismounting detection means for detecting mounting and dismounting of the sheet loading tray 110, a sheet presence or absence detection means provided on a conveyance passage for fed sheet to detect presence or absence of sheet, and a paper feeding delay jam detection means for determining that paper feeding delay/jam occurs when the sheet presence or absence detection means does not detect a tip of sheet within predetermined time from start of paper feeding when feeding paper from the paper feeding device. While the paper feeding delay jam detection means detects paper feeding delay/jam and paper is in a jam condition, this image forming device returns from the jam condition when a sheet loading tray mounting detection means detects the presence of a mounting condition of the sheet loading tray 110 again after the mounting condition of the sheet loading tray 110 is changed from presence to absence. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus, and particularly relates to ease and simplification of jam release.

2. Description of the Related Art Conventionally, in an image forming apparatus, in order to recover from a jammed state, a user performs opening and closing of an apparatus cover, a door, and the like necessary for attaching and detaching a cartridge. On the other hand, in order to realize the simplification of the jam release, there is one that recognizes that the paper presence / absence sensor that has existed at the time of the jam occurrence has changed to no paper and performs the jam release (for example, Patent Document 1). See). Further, in the automatic document feeder of the image forming apparatus, the jam is canceled by removing the jammed document (see, for example, Patent Document 2).
JP 7-215533 A Japanese Patent Laid-Open No. 6-80276

However, with the conventional jam release method,
1. When opening and closing the apparatus cover necessary for attaching and detaching the cartridge, it is necessary to always drive the drum to perform cleaning and initialization of the electrophotographic process, which may require extra operations. Also, when a paper feed delay jam or the like occurs due to a pickup failure when feeding paper from the paper cassette, the operation of opening and closing the device cover after removing and removing the paper cassette and removing the jammed paper is performed. It was necessary.

  2. Also, when detecting the removal of jammed paper for jamming simplification and releasing jamming, a detection mechanism (sensor) is required to detect the presence of paper on the transport path when a jam occurs. Thus, when a paper feed delay jam or the like occurs from the paper feed cassette, it cannot be an effective solution because there is no sensor for detecting the presence or absence of paper among the sensors on the transport path.

  Accordingly, an object of the present invention is to achieve a usability improvement by simplifying a jam clearing method when a paper feed delay jam occurs.

  In order to achieve the above object, the first invention according to the present application is performed by attaching / detaching (removing / inserting) a cassette bag (paper feed tray) of a paper feeding device in which a paper feeding failure has occurred as a paper jam release method. It is characterized by that.

  The second invention according to the present application is characterized in that the paper feeding delay jam is canceled by attaching and detaching a paper feeding device in which a paper feeding failure has occurred.

  The first invention of the present invention will be described in more detail as follows.

(1) A sheet feeding device having a sheet stacking tray on which one or more sheets can be stacked, a sheet stacking tray attachment / detachment detecting unit for detecting attachment / detachment of the sheet stacking tray, and conveyance of the fed sheet A sheet presence / absence detection unit that detects the presence / absence of a sheet provided on the road, and the sheet presence / absence detection unit does not detect the leading edge of the sheet within a predetermined time when feeding from the sheet feeding device. A paper feed delay jam detecting means for judging a paper feed delay jam,
When the paper feed delay jam detection unit detects a paper feed delay jam and is in a jammed state, the sheet stacking tray mounting detection unit detects that the sheet stacking tray mounting state has changed after the mounting state of the sheet stacking tray has changed from present to none. An image forming apparatus that recovers from a jammed state at the time of detection.

  As described above, according to the first aspect of the present invention, when a paper feed delay jam occurs, a jam can be reliably caused by attaching / detaching (removing) the cassette cage of the paper feed device on which the jammed paper is present. The paper can be found and removed, and the jammed state can be canceled without any other operation. In addition, since a detection mechanism (sensor) for detecting attachment / detachment of an existing paper feed cassette can be substituted without adding a sensor for recognizing jam release on the transport path, the usability can be improved without increasing new costs. Can do.

  According to the second aspect of the present invention, when a paper feed delay jam occurs, the jam paper can be reliably found and removed by attaching and detaching (removing / inserting) the paper feed device on which the jam paper exists. The jam state can be canceled without any other operation. In addition, since a detection mechanism (sensor) for detecting attachment / detachment of an existing paper feed cassette can be substituted without adding a sensor for recognizing jam release on the transport path, the usability can be improved without increasing new costs. Can do.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

  Of the image forming apparatuses, a printer will be described as an example. The printer has a mechanism as shown in FIG. In FIG. 1, 101 is a photosensitive drum as an electrostatic carrier, 102 is a semiconductor laser as a light source, 103 is a rotating polygon mirror that is rotated by a scanner motor 104, and 105 is emitted from the semiconductor laser 102. It is a laser beam that scans the top.

  Reference numeral 106 denotes a charging roller for uniformly charging the surface of the photosensitive drum 101, and reference numeral 107 denotes a developing unit for developing the electrostatic latent image formed on the photosensitive drum 101 with toner. Reference numeral 108 denotes a transfer roller for transferring the toner image developed by the developing unit 107 to a predetermined recording sheet, and reference numeral 109 denotes a fixing unit for fusing the toner transferred to the recording sheet by heat.

  110 is a paper feed cassette for storing paper, 111 is a cassette mounting sensor (which may be a sensor for identifying the paper size) for detecting that the paper feed cassette 110 is mounted, and 112 is rotated once. Pickup rollers for feeding paper from the paper feed cassette 110 and feeding it to the conveyance path, 113 and 114 are rollers for reliably separating the paper picked up by the pickup roller 112 into one sheet and feeding it to the conveyance path Reference numeral 113 denotes a feed roller, reference numeral 114 denotes a retard roller, and reference numeral 115 denotes an intermediate roller for conveying the paper fed from the feed retard roller pair to the image forming unit.

  116 Pre-feed sensor for detecting the leading and trailing edges of the sheet conveyed by the intermediate roller 115, 117 a pre-transfer roller for feeding the conveyed sheet to the photosensitive drum 101, and 118 for the fed sheet This is a top sensor for synchronizing the image writing (recording / printing) on the photosensitive drum 101 and the sheet conveyance and measuring the length of the fed sheet in the conveyance direction. 119 is a fixing sensor for detecting the presence or absence of a sheet after fixing, 120 is a conveying roller for discharging the fixed sheet to a sheet discharging conveyance path, and 122 is a sheet discharged from the discharging roller to the sheet discharging tray 121. Therefore, the paper discharge reversing roller reverses when the paper is fed to the normal rotation / removable double-sided unit 123, 124 is a double-side introduction roller for feeding the paper fed from the paper discharge reversing roller 120 to the double-sided conveyance unit, and 125 is double-sided A double-sided conveyance roller 126 in the conveyance unit is a refeed sensor for detecting the paper conveyance state of the double-sided conveyance unit.

  127 is an optional paper feed cassette that can be attached to and detached from the printer, 128 is an optional paper feed cassette for storing 128 paper, and 129 is a cassette mounting sensor that detects that the optional paper feed cassette 128 is installed (however, it identifies the paper size). The sensor 130 may be rotated once to feed paper from the optional paper feed cassette 桶 128 and feed the paper to the transport path, and 131 and 132 reliably feed the paper picked up by the pick-up roller 130. A pair of rollers for separating the sheet into one sheet and feeding it to the conveyance path, 131 is a feed roller, and 132 is a retard roller.

  FIG. 2 shows a block diagram of a circuit configuration of a control system that controls such a mechanism unit. In FIG. 2, reference numeral 200 denotes a printer main body, 201 denotes image code data sent from an external device such as a host computer (not shown), which is developed into bit data necessary for printer printing, and also reads internal printer information and displays it. This is a printer controller.

  A printer engine control unit 202 controls the printing operation of each unit of the printer engine in accordance with an instruction from the printer controller 201 and notifies the printer controller 201 of printer internal information. A high-voltage control unit 203 performs high-voltage output control in each process such as charging, development, and transfer in accordance with an instruction from the printer engine control unit 202. An optical system control unit 204 controls driving / stopping of the scanner motor 104 and lighting of the laser beam in accordance with instructions from the engine control unit 202. Reference numeral 205 denotes a fixing device controller that drives / stops energization of the fixing heater in accordance with an instruction from the printer engine controller 202.

  A sensor input unit 206 notifies the engine control unit 202 of the presence / absence state of the pre-feed sensor 116, the top sensor 118, and the paper discharge sensor 119 and the detection result of the paper feed cassette 桶 detection sensor 111, and 207 is a printer engine control unit. In accordance with an instruction 202, a sheet conveyance control unit for driving / stopping a motor or a roller (not shown) for conveying a recording sheet, a sheet feeding roller 112, a feed roller 113, a retard roller 114, an intermediate roller in FIG. 115, controls the driving / stopping of the pre-transfer roller 117, the fixing roller 109, the discharge roller 120, and the double-side introduction roller 124.

  Reference numeral 208 denotes a duplex unit 123 which can be attached to and detached from the printer main body 200. Reference numeral 209 denotes a mechanism for driving the duplex transport roller 125 in the duplex transport unit in accordance with an instruction from the engine control unit 202 and detecting the paper transport state of the duplex transport unit. This is a duplex unit control unit that notifies the engine control unit 202 of the information of the refeed sensor 126 via serial communication (not shown).

  Reference numeral 210 denotes an optional paper feed cassette 127 that can be attached to and detached from the printer main body 200. Reference numeral 211 denotes an option cassette paper feed roller 130, a feed roller 131, and a retard roller 132 that are driven in accordance with instructions from the engine control unit 202. This is an option cassette control unit for notifying the engine control unit 202 of the information and the mounting state of the optional sheet cassette 桶 128 via serial communication (not shown).

  FIG. 3 shows a flowchart of the printing and paper feed delay jam detection sequence of the engine control unit 202 in this embodiment. In FIG. 3, it is monitored whether or not a print instruction has been received from the printer controller 201 that has received print data from an external device (not shown). When a print instruction is issued from an external device (not shown), the printer controller 201 issues a print instruction after instructing the engine control unit such as a paper size and a paper feed port.

  After confirming the print instruction, the engine control unit 202 starts up an electrophotographic process at 302. At 303, the start of the electrophotographic process is awaited. When the completion of the electrophotographic process is confirmed at 303, a paper feed start operation is performed from the paper feed port designated at 304. When the paper feed opening is a paper feed cassette, the pickup roller 112 is rotated once to pick up the paper stacked on the paper feed cassette 桶 110, and the feed retard roller 113 and the retard roller 114 are driven to carry the paper. When the paper feed port designated by the printer controller is the optional paper feed cassette 127, the optional pickup roller 130 is rotated once to pick up the paper loaded on the optional paper feed cassette 桶 128, and the rollers of the feed roller 131 and the retard roller 132 are picked up. The pair is driven to feed the paper.

  In 305, a timer for measuring the paper feed time is started simultaneously with the start of paper feed. In 306, the pre-feed sensor 116 detects whether the paper feeding operation has been normally performed by detecting the leading edge of the paper that has started feeding. Reference numeral 307 monitors a timer value that is started simultaneously with the start of paper feed. This is because the paper feed conveyance distance differs depending on the paper feed port, and the timer value counted for each paper feed port is different.

  If the prefeed sensor detects the leading edge of the fed sheet at 306, the processing at 308 is performed. When the top sensor 118 detects the leading edge of the paper at 308, the printer controller 201 is notified, and image formation is started in synchronization with the printer controller 201.

  In step 309, it is monitored whether there is a print instruction for the subsequent sheet. If there is a print instruction for the succeeding paper, the process 304 is repeated after a predetermined time has elapsed from the start of printing. If there is no print instruction for the succeeding paper, the process waits for the completion of printing at 310. When the completion of printing is detected at 310, the paper is discharged to the paper discharge tray at 311 and the electrophotographic process is lowered. End the printing operation.

  If the pre-feed sensor 116 cannot detect the leading edge of the paper at 306 even after a lapse of a predetermined time from the start of paper feeding at 307, it is recognized at 312 that a paper feed failure has occurred ( In this case, since the pickup roller 112 and the optional cut pickup roller 130 may be swung, the paper feed retry operation may be performed a plurality of times. The paper feed delay jam is determined, the printer controller 201 is notified, and the instructed printing is performed. Notify that the operation did not end normally. At this time, the printer controller 201 can display the fact that a paper feed delay jam has occurred on a display panel (not shown) or the like so that the optimum jam processing method can be known. (In the present embodiment, it is optimal to pull out the cassette bag after printing is completed and check the stacked state of the paper.) After continuous jamming, if continuous printing is in progress, whether the printing of the preceding paper has been completed is 313. If the preceding paper is being printed, it waits for the preceding paper to be printed. If the printing of the preceding paper has been completed, the process of lowering the electrophotographic process is performed at 314, and if there is a preceding paper, the preceding paper is discharged to the paper discharge tray and transitions to the jam state.

  In order to cancel the jammed state, first, at 315, it is detected that the paper feed cassette has been pulled out. If the sheet feeding port that has been performing the sheet feeding operation is a sheet feeding cassette, the cassette loading sensor 111 detects that the sheet feeding cassette basket 110 has been pulled out. If the paper feed port that was performing the paper feed operation is the optional paper feed cassette 127, it is monitored that the optional paper feed cassette mounting sensor 129 detects that the optional paper feed cassette basket 128 has been pulled out. After detecting the removal of the paper cassette cassette 315 at 315, it is monitored at 316 that the paper cassette is reattached, and when the paper cassette is reattached, the user confirms the paper stacking state of the cassette cage 110 or 128 and If there is, it is determined that the correction has been made. At 317, the jam state is canceled and the printer controller 201 is notified of the jam state cancellation.

  In the first embodiment, the cassette bag is physically attached / detached and the physical attachment / detachment is detected by a switch or a sensor. In this embodiment, a case of an optional sheet feeding unit that can be attached and detached by serial communication will be described.

  Of the image forming apparatuses, a printer will be described as an example. The printer has a mechanism as shown in FIG. In FIG. 4, 401 is a photosensitive drum as an electrostatic carrier, 402 is a semiconductor laser as a light source, 403 is a rotating polygon mirror rotated by a scanner motor 404, and 405 is emitted from the semiconductor laser 402, and is a photosensitive drum 401. It is a laser beam that scans the top.

  Reference numeral 406 denotes a charging roller for uniformly charging the surface of the photosensitive drum 401, and reference numeral 407 denotes a developing unit for developing the electrostatic latent image formed on the photosensitive drum 401 with toner. Reference numeral 408 denotes a transfer roller for transferring the toner image developed by the developing unit 407 to a predetermined recording sheet, and 409 denotes a fixing unit for fusing the toner transferred to the recording sheet by heat.

  410 is a paper feed cassette for storing paper, 411 is a cassette mounting sensor for detecting that the paper feed cassette 410 is mounted (it may be a sensor for identifying the paper size), and 412 is rotated once. Pickup rollers for feeding paper from the paper feed cassette 410 and feeding it to the transport path 413 and 414 are rollers for reliably separating the paper picked up by the pickup roller 412 into one sheet and feeding it to the transport path Reference numeral 413 denotes a feed roller, reference numeral 414 denotes a retard roller, and reference numeral 415 denotes an intermediate roller for conveying the paper fed from the feed retard roller pair to the image forming unit.

  416 Pre-feed sensor for detecting the leading and trailing edges of the sheet conveyed by the intermediate roller 415, 417 a pre-transfer roller for feeding the conveyed sheet to the photosensitive drum 401, and 418 for the fed sheet This is a top sensor for synchronizing the image writing (recording / printing) to the photosensitive drum 401 and the sheet conveyance and measuring the length of the fed sheet in the conveyance direction. 419 is a fixing sensor for detecting the presence or absence of a sheet after fixing; 420 is a conveying roller that discharges the sheet after fixing to a sheet discharging conveyance path; 422 is a sheet that is conveyed from the discharging roller to the sheet discharging tray 421; Therefore, the paper reversing roller 424 reverses when the paper is fed into the normal / removable double-sided unit 423, 424 is a double-sided introduction roller for feeding the paper fed from the paper discharging reversing roller 420 to the double-sided conveyance unit, and 425 is double-sided. Double-sided conveyance rollers 426 in the conveyance unit are re-feed sensors for detecting the paper conveyance state of the double-sided conveyance unit.

  427 is an optional paper feed cassette detachable from the printer, 428 is an optional paper feed cassette for storing 428 paper, and 429 is a cassette mounting sensor for detecting that the optional paper feed cassette 428 is mounted (however, the paper size is identified. (A sensor may also be used) 430 rotates once to feed paper from the optional paper feed cassette 桶 428 and feeds it to the conveyance path, and 431 and 432 reliably pick up the paper picked up by the pickup roller 430. A pair of rollers for separating the sheet into one sheet and feeding it to the conveyance path, 431 is a feed roller, and 432 is a retard roller.

  Reference numeral 433 denotes a removable option envelope feeder. Reference numeral 434 denotes an envelope stacking tray for stacking sheets on the envelope feeder, 435 denotes envelope feeder pickup rollers for picking up the sheets by driving the lowermost sheet loaded on the envelope stacking tray 434 in a normal direction for a predetermined time, 436 and 437 The roller pair is a roller for reliably separating only one sheet picked up by the envelope feeder pickup roller 435 and transporting it to the pre-transfer roller 417, 436 being an envelope feeder retard roller, and 437 being an envelope feeder feed roller. .

  FIG. 5 shows a block diagram of a circuit configuration of a control system for controlling such a mechanism unit. In FIG. 2, reference numeral 500 denotes a printer main body, 501 is used to develop image code data sent from an external device such as a host computer (not shown) into bit data necessary for printer printing, and to read and display printer internal information. This is a printer controller.

  A printer engine control unit 502 controls the printing operation of each unit of the printer engine in accordance with an instruction from the printer controller 501 and notifies the printer controller 501 of printer internal information. Reference numeral 503 denotes a high voltage control unit that performs high voltage output control in each process such as charging, development, and transfer in accordance with an instruction from the printer engine control unit 502. An optical system control unit 504 controls driving / stopping of the scanner motor 404 and lighting of the laser beam in accordance with an instruction from the engine control unit 502. Reference numeral 505 denotes a fixing device control unit that drives / stops energization of the fixing heater in accordance with an instruction from the printer engine control unit 502.

  Reference numeral 506 denotes a sensor input unit for notifying the engine control unit 502 of paper presence / absence states of the pre-feed sensor 416, the top sensor 418, and the paper discharge sensor 419 and the detection result of the paper feed cassette detection sensor 411. Reference numeral 507 denotes a printer engine control unit. In accordance with an instruction 502, a paper conveyance control unit that drives / stops a motor or a roller (not shown) for conveyance of recording paper, and feed roller 412, feed roller 413, retard roller 414, intermediate roller in FIG. 415 controls the driving / stopping of the pre-transfer roller 417, the fixing roller 409, the discharge roller 420, and the double-side introduction roller 424.

  Reference numeral 508 denotes a duplex unit 423 that can be attached to and detached from the printer main body 500, and 509 is for driving the duplex transport roller 425 in the duplex transport unit and detecting the paper transport state of the duplex transport unit in accordance with an instruction from the engine control unit 502. This is a duplex unit control unit that notifies the engine control unit 502 of information of the refeed sensor 426 via serial communication (not shown).

  Reference numeral 510 denotes an optional paper feed cassette 427 that can be attached to and detached from the printer main body 500. Reference numeral 511 denotes an option cassette paper feed roller 430, a feed roller 431, and a retard roller 432 that are driven in accordance with instructions from the engine control unit 502. This is an option cassette control unit for notifying the engine control unit 502 of the information and the mounting state of the option sheet cassette 428 via serial communication (not shown).

  Reference numeral 512 denotes an optional envelope feeder 433 that can be attached to and detached from the printer main body 500. Reference numeral 513 denotes an optional envelope feeder pickup roller 435, envelope feeder retard roller 436, and envelope feeder 437 that are driven according to instructions from the engine control unit 502, and paper presence / absence information is not shown. It is an envelope feeder control unit that notifies the engine control unit 502 via serial communication.

  FIG. 6 shows an electrical connection diagram of the duplex unit control unit 509 connectable to the engine control unit 502, the connectable option cassette control unit 511, and the connectable envelope feeder control unit 513. In FIG. 6, 601 is a DC power supply for supplying power to each connectable unit, 602 is a GND common to each connectable unit, and 603 is one CLK with each connectable unit and three-wire serial communication. 604 is a CMD signal, and 605 is an STS signal. Since these three-wire serial communication has a common signal line, there is a / SEL signal provided for the engine control unit 502 to perform individual communication with each unit. 606 is a duplex unit / SEL signal for serial communication with the duplex unit, 607 is an option cassette / SEL signal for serial communication with the option cassette, and 608 is an envelope feeder / SEL signal for serial communication with the envelope feeder. It is.

  FIG. 7 shows a basic timing chart for serial communication with each option. In FIG. 7, for example, when the engine control unit 502 performs serial communication with the envelope feeder control unit 513, first, the envelope feeder / SEL signal is first set to the “LOW” level. Thereafter, the data is synchronized with the CMD signal while outputting the CLK signal. After outputting eight CLK signals, the / SEL signal is set to “HIGH” level to transmit a command.

  In order to receive the status data from the envelope feeder, first, the engine control unit 502 sets the / SEL signal to the “LOW” level. Since eight CLK signals are output thereafter, the envelope feeder control unit 513 puts 8-bit stator data on the STS signal bit by bit in synchronization with the falling edge. The engine control unit 502 receives 8-bit status data by reading the level of the STS signal in synchronization with the rising edge of the CLK signal. When the reception of the status data is completed, the / SEL signal is set to the “HIGH” level and data is transmitted and received once.

  Since the STS signal line is normally at the “HIGH” level, when a unit for serial communication (for example, an envelope feeder) is not connected, the return status data for the serial communication command is always “0xFF”. Therefore, the engine control unit 502 determines that the unit is not connected when data “0xFF” is received as a return status for the command, and conversely, when data other than “0xFF” is received, the unit is normally connected. to decide.

  FIG. 8 shows a flowchart of the printing and paper feed delay jam detection sequence of the engine control unit 502 in this embodiment. In FIG. 8, it is monitored whether or not a print instruction has been received from the printer controller 501 that has received print data from an external device (not shown). When a print finger is instructed from an external device (not shown), the printer controller 501 issues a print instruction after instructing the paper size, paper feed port, and the like to the engine control unit.

  After confirming the print instruction, the engine control unit 502 starts the electrophotographic process at 802. At 803, the start-up of the electrophotographic process waits for completion. When the end of the electrophotographic process is confirmed in 803, a paper feed start operation is performed from the envelope feeder 433 in 804. The pickup roller 435 is rotated for a predetermined time to pick up the paper from the lowermost stage of the paper loaded from the envelope stacking tray 434, and the paper is conveyed to the envelope feeder feed retard roller pair 436, 437 and reliably 1 by the feed retard roller pair. The sheet is separated and conveyed to a pre-transfer roller 417 for paper feeding.

  In 805, a timer for measuring the paper feed time is started simultaneously with the start of paper feed. In step 806, the top sensor 418 detects whether the paper feeding operation has been normally performed by detecting the leading edge of the paper that has been fed. Reference numeral 807 monitors a timer value started simultaneously with the start of paper feeding.

  If the prefeed sensor detects the leading edge of the fed sheet at 806, the processing at 808 is performed. When the top sensor 418 detects the leading edge of the paper at 808, the printer controller 501 is notified, and image formation is started in synchronization with the printer controller 501.

  In step 809, it is monitored whether there is a print instruction for the subsequent sheet. If there is a print instruction for the subsequent paper, the process of 804 is repeated after a predetermined time has elapsed from the start of printing. If there is no print instruction for the succeeding paper, it waits for the printing to end at 810. When the printing end is detected at 810, the paper is discharged to the paper discharge tray at 811 and the electrophotographic process is lowered. End the printing operation.

  If the top sensor 418 cannot detect the leading edge of the paper at 806 even after a predetermined time has elapsed since the start of paper feeding at 807, it is recognized at 812 that a paper feeding failure has occurred (this In this case, the pickup roller 435 may be swung, etc., so that the paper feeding retry operation may be performed a plurality of times. A paper feeding delay jam is determined, the printer controller 501 is notified, and the instructed printing operation does not end normally. Contact me. At this time, the printer controller 501 can display the fact that a paper feed delay jam has occurred on a display panel (not shown) and can know the optimum jam processing method. (In this embodiment, it is optimal to pull out the cassette bag after printing is completed to check the paper stacking state.) After continuous jamming, if continuous printing is in progress, 813 indicates whether printing of the preceding paper has been completed. If the preceding paper is being printed, it waits for the preceding paper to be printed. If the preceding paper has been printed, the electrophotographic process is lowered at 814. If there is a preceding sheet, the preceding sheet is discharged to the paper discharge tray and transitions to the jam state.

  In order to cancel the jammed state, first, in 815, it is detected that the envelope feeder 433 has been removed. This is detected when the status of serial communication performed with the envelope feeder control unit 513 returns “0xFF”. After detecting that the envelope feeder is detached at 815, it is monitored that it is reattached at 816 (reattachment is performed again with status data other than “0xFF” by serial communication performed with the envelope feeder controller 513) The user confirms the paper stacking state of the envelope feeder at the time of remounting, and determines that the correction has been made if there is an abnormality. In 817, the jam state is released and the printer controller 501 is notified of the release of the jam state.

It is a block diagram explaining the mechanism which concerns on the 1st Example of this invention. 1 is a block diagram illustrating a circuit configuration according to a first embodiment of the present invention. It is a flowchart figure explaining the sequence which concerns on 1st Example of this invention. It is a block diagram explaining the mechanism which concerns on 2nd Example of this invention. It is a block diagram explaining the circuit structure based on the 2nd Example of this invention. It is an electrical connection diagram explaining the electrical connection which concerns on the 2nd Example of this invention. It is a time chart explaining the communication form which concerns on 2nd Example of this invention. It is a flowchart figure explaining the sequence which concerns on the 2nd Example of this invention.

Explanation of symbols

110 cassette (paper tray)
111 cassette 桶 (paper feed tray) attachment / detachment detection sensor 127 optional paper feed cassette 128 optional paper feed cassette 桶 129 option paper feed cassette attachment / detachment detection sensor

Claims (2)

A sheet feeding device having a sheet stacking tray on which one or more sheets can be stacked, a sheet stacking tray attachment / detachment detecting unit for detecting attachment / detachment of the sheet stacking tray, and a feeding path for the fed sheet Sheet presence / absence detecting means for detecting the presence / absence of a sheet, and paper feeding if the sheet presence / absence detecting means does not detect the leading edge of the sheet within a predetermined time when feeding from the paper feeding device. A paper feed delay jam detection means for determining a delay jam,
When the paper feed delay jam detection unit detects a paper feed delay jam and is in a jammed state, the sheet stacking tray mounting detection unit detects that the sheet stacking tray mounting state has changed after the mounting state of the sheet stacking tray has changed from present to none. An image forming apparatus that recovers from a jammed state at the time of detection. A sheet feeding device having one or more sheets having a stacking tray, a sheet stacking tray attachment / detachment detecting unit for detecting attachment / detachment of the sheet feeding device, and a sheet feeding path for detecting the presence / absence of a sheet. Sheet presence / absence detection means and a paper feed delay that determines a paper feed delay jam if the sheet presence / absence detection means does not detect the leading edge of the sheet within a predetermined time when feeding from the paper feeding device. Jam detection means,
When the paper feed delay jam detection means detects a paper feed delay jam and is in a jammed state, the paper feed device attachment detection means is again present after the paper feed device attachment state changes from present to none. An image forming apparatus that recovers from a jammed state at the time of detection.

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