JP4777092B2 - Paper transport device for electrophotographic apparatus - Google Patents

Description

  The present invention relates to a paper transport device of an electrophotographic apparatus, and more particularly to a paper transport device of an electrophotographic apparatus that detects a paper jam.

  As shown in FIG. 9, the conventional sheet conveying apparatus of the electrophotographic apparatus includes a conveying path 104 on which the sheet P is conveyed, and a pair of a fixing roller 101 and a pressure roller 102 constituting a fixing device. . The fixing roller 101 is provided with a temperature sensor 103 that detects its temperature. The sheet conveying apparatus includes an outlet sensor 105 and an inlet sensor 106 as flag type sensors provided on the conveying path 104 on the upstream side and the downstream side of the fixing device. The exit sensor 105 detects the paper P that has been fixed through the fixing nip portion of the fixing roller 101 and the pressure roller 102, and the entrance sensor 106 detects the paper due to a paper jam such as the paper P being wrapped around the fixing roller 101. The conveyance stop of P is detected (for example, Patent Document 1).

In addition, when transferring a toner image formed on a photosensitive drum constituting an image forming unit onto a sheet P, the conventional electrophotographic apparatus conveys the sheet P while adsorbing to the photosensitive drum, and on the downstream side. Although the paper P is separated by applying a separation bias, the paper P may be wound around while being adsorbed to the photosensitive drum due to poor separation. Therefore, a flag type sensor similar to the above is provided on the upstream side of the photosensitive drum to detect a paper jam due to the winding of the paper P around the photosensitive drum.
Japanese Patent Laid-Open No. 05-088586

  However, in the above-described prior art, the flag type sensor provided on the entrance side may make the entry angle when the paper P enters the fixing nip portion unstable, and in recent years, the need for thin paper such as recycled paper has increased. In the meantime, such a weak paper makes the entry angle unstable.

In addition, as the printing speed increases, the paper transport distance required for the fixing roller to stop when paper jams such as wrapping around the fuser become longer. In some cases, it may enter the vicinity of the nip. On the other hand, if the sensor provided on the entrance side of the fixing device is arranged as close to the fixing device as possible , the failure of the sensor due to heat and the influence on the life become a problem.

  Similarly to the above, the flag type sensor provided on the upstream side of the photosensitive drum in the electrophotographic apparatus also makes the angle of the paper entering the transfer portion unstable and causes a transfer defect.

  An object of the present invention is to provide a paper transport device of an electrophotographic apparatus that can eliminate the need for a paper jam detection sensor provided on the transport path.

In order to achieve the above object, a paper transport device of an electrophotographic apparatus according to the present invention is a roller that is provided in the transport path in the paper transport device of an electrophotographic apparatus that transports a paper along a transport path and through which the paper passes. Provided on the upstream side of the pair and the roller pair, movable to a position in the transport path and a position outside the transport path, and moved to a position in the transport path to check whether or not there is paper in the transport path a sheet detection means for detecting, in a state where the sheet detecting means is moved to a position outside the conveying path, a paper jam of the sheet at the position of the roller pair by a sensor for detecting the sheet other than the sheet detecting means If detected, after stopping the conveying operation, wherein the sheet detecting means is moved into the conveying path, when the paper detecting means has not detected the sheet, and the sheet to the rollers is wound around Sir Outputs service call stores the abnormality that represents a squall, when the paper detecting means is detecting the sheet, possess a controlling means for requesting the paper jam removal process, the said control means, said electronic When the photographic apparatus is turned on, the paper detection means is moved into the paper conveyance path, and if the paper detection means does not detect the paper and an abnormality represented by the service call is stored, a service call is output. It is characterized by doing.

According to the present invention, it is possible to the sensor for paper jam detection paper provided on conveyance path unnecessary, as a result, although it is possible to prevent a paper jam conveys the sheet stably In addition, it is possible to prevent sensor failure and influence on the service life.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram schematically showing a configuration of a sheet conveying apparatus according to a first embodiment of the present invention.

  In FIG. 1, a sheet conveying apparatus 100 of an electrophotographic apparatus includes a conveying path 104 on which a sheet P is conveyed, a pair of a fixing roller 101 and a pressure roller 102 that constitute a fixing device on the conveying path 104, And an outlet sensor 105 provided in the conveyance path 104 on the downstream side of the fixing device. The fixing roller 101 is provided with a temperature sensor 103 that detects its temperature. The exit sensor 105 detects the paper P that has been fixed through the fixing nip portion between the fixing roller 101 and the pressure roller 102.

  The sheet conveying apparatus 100 further includes a winding detection sensor 201 provided below the conveyance path 104, a winding detection sensor motor 202 provided to move the winding detection sensor 201 in the vertical direction, and a home position (HP). A sensor 203. The HP sensor 203 detects that the winding detection sensor 201 that moves in the vertical direction is at a predetermined home position position outside the transport path 104. The paper transport apparatus 100 also includes a fixing motor 307 that rotates the fixing roller 101 and a paper transport motor 308 that transports the paper P (FIG. 2).

  The exit sensor 105, the winding detection sensor 201, the HP sensor 203, the fixing motor 307, the paper conveyance motor 308, and the winding detection sensor motor 202 are controlled by the control device (FIG. 2) of the paper conveyance device 100, respectively.

  FIG. 2 is a functional block diagram of the control device of the paper transport apparatus 100 of FIG.

  The control device 300 of the paper transport apparatus 100 includes a CPU 301, a ROM 302, a RAM 303, an input / output port (PIO) 304, an ASIC 305, and a motor driver 306, which are connected to each other via a system bus.

  The CPU 301 generally controls this apparatus. The ROM 302 stores the control program of the CPU 301, and the RAM 303 stores data temporarily stored in the control flow of the CPU 301, adjustment data unique to the apparatus, and the like.

  The PIO 304 inputs detection signals from the exit sensor 105, the winding detection sensor 201, and the HP sensor 203. On the other hand, the ASIC 305 controls the fixing motor 307, the paper transport motor 308, and the winding detection sensor motor 202 via the motor driver 306. However, the start timing and stop timing of each motor are controlled by instructions from the CPU 301.

  Hereinafter, the winding detection process executed by the paper conveying apparatus 100 of FIG. 1 will be described with reference to FIGS.

<Winding detection sensor home position control process>
FIG. 3 is a flowchart showing a procedure of the wrapping detection sensor home position control process executed by the paper conveying apparatus 100 of FIG.

  In FIG. 3, first, when the power is turned on (step S101), the home position (HP) control is started so that the winding detection sensor 201 stands by at the home position outside the desired transport path 104 (step S102). Next, the CPU 301 determines whether or not the HP sensor 203 detects a part of the member to which the winding detection sensor 201 is attached based on the stored value of the PIO 304 (step S103). If it is detected as a result of the determination in step S103, the winding detection sensor 201 is moved upward until the HP sensor 203 does not detect the detection (step S104), and the determination in step S103 is repeated. When the HP sensor 203 is no longer detected (NO in step S103), the winding detection sensor 201 is again moved downward (step S106), and the HP sensor 203 is one of the members to which the winding detection sensor 201 is attached again. Is detected (NO in step S107), the wrapping detection sensor motor 202 is operated by a predetermined pulse to stop (step S108), and this process is terminated.

  In the present embodiment, the case where the winding sensor home position control process is performed immediately after the power is turned on is described. However, the return timing is not limited to immediately after the power is turned on, but is performed after the paper transport paper jam process or after the abnormal stop of the main body. May also be applied.

<Turning control process at power-on>
FIG. 4 is a flowchart showing a procedure of a power-on winding control process executed by the paper conveying apparatus of FIG.

  This process is executed after the winding sensor home position control process of FIG.

  4, first, when the power-on winding control process is started (step S201), the winding detection sensor 201 starts to move toward the conveyance path 104 (step S202). At this time, since the winding detection sensor 201 is moved from the home position, the winding detection sensor 201 is moved by a predetermined pulse so that the paper in the transport path comes into contact (step S203). Next, the presence or absence of the paper P is detected by the winding detection sensor 201 (step S204). When the paper P is detected, a paper jam processing shown in FIG. 6 to be described later is requested to prohibit the processing operation of the apparatus (step S204). S205), the process is terminated.

  If the result of the determination in step S204 is that there is no paper P, it is determined based on the information stored in the RAM 303 whether or not an unprocessed service call has been issued when the power was last turned off (step S206). . If no unprocessed service call (service correspondence error) has been issued as a result of the determination in step S206, there is no abnormality in the apparatus, so the fixing temperature adjustment control and other standby control are executed (step S208). The process ends. If there is an unprocessed service call (service correspondence error) as a result of the determination in step S206, there is a possibility that the unprocessed paper P is wound around the fixing roller 101. Is stopped (step S207), and this process is terminated.

<Winding detection control process when fixing paper jam stops>
FIG. 5 is a flowchart showing the procedure of the process for detecting the wrapping at the time of stopping the fixing paper jam, which is executed by the paper conveying device of FIG.

  This process is executed when a fixing paper jam occurs during operation of the apparatus.

  In FIG. 5, first, when a fixing paper jam occurs and the apparatus stops (step S301), the winding detection sensor 201 starts to move toward the conveyance path 104 (step S302). At this time, since the winding detection sensor 201 is moved from the home position, the winding detection sensor 201 is moved by a predetermined pulse so that the paper in the transport path comes into contact (step S303). Next, the presence or absence of the paper P is detected by the winding detection sensor 201 (step S304). When the paper P is detected, the paper jam processing shown in FIG. S305), this process is terminated.

  As a result of the determination in step S304, when there is no paper P, there is a possibility that the paper is wound around the fixing roller 101. Therefore, the service abnormality is stored in the RAM 303 (step S306), and a service man call is output. The operation of the apparatus is stopped (step S307), and the service call is continuously issued until the processing by the service person is completed. After the service is completed (YES in step S308), the service abnormality stored in the RAM 303 is deleted. (Step S308), the apparatus is operated (Step S309), and this process is terminated.

  According to the processing of FIG. 4 or 5, the presence or absence of the paper P in the transport path 104 is detected at a desired timing by the wrapping detection sensor 201, so that a paper jam detection sensor provided on the transport path 104 is not required. As a result, the paper P can be stably conveyed and paper jams can be prevented, and in addition, sensor failure and influence on the service life can be prevented.

  FIG. 6 is a flowchart showing the procedure of paper jam processing required in step S205 of FIG. 4 or step S305 of FIG.

  In FIG. 6, when there is a paper jam request in the processing of FIG. 4 or FIG. 5 (step S305), if it is detected that the door is opened by the user (YES in step S402), the winding detection sensor 201 is detected. Is placed on the outside of the transport path 104 (step S403). This is because when the user processes the paper P to the upstream side of the fixing device for paper jam processing, the member connected to the winding detection sensor 201 is caught by the paper jammed paper. This is in order not to bother the clogging work.

  Next, when it is detected that the door is closed (YES in step S404), the winding detection sensor 201 is moved again into the transport path 104 (step S405), and the presence or absence of the paper P is detected by the winding detection sensor 201 (step S405). S304) When the paper P is detected, it is determined that the paper jam processing has not yet been completed, and the processing from step S401 is repeated. When the paper P is not detected, the paper jam processing has been normally completed. Judgment is made, the apparatus is operated (step S407), and this process is terminated.

  FIG. 7 is a diagram schematically showing a configuration of a sheet conveying apparatus according to the second embodiment of the present invention.

  In FIG. 7, a sheet conveying apparatus 900 of an electrophotographic apparatus includes a conveying path 904 on which a sheet P is conveyed, and a pair of a photosensitive drum 901 and a transfer roller 902 that constitute a transfer unit on the conveying path 904. Prepare. The photosensitive drum 901 carries a toner image that has been charged, exposed, and developed by electrophotography, and the transfer roller 902 rotates in opposition to the photosensitive drum 901 to transfer the toner image on the photosensitive drum to a sheet. A bias is applied at the time of transfer.

  The paper conveyance device 900 further includes a winding detection sensor 911 provided below the conveyance path 904, a winding detection sensor motor 912 provided to move the winding detection sensor 911 in the vertical direction, and a home position (HP). A sensor 913. The HP sensor 913 detects that the winding detection sensor 911 moving in the vertical direction is at a predetermined home position outside the conveyance path 904. The paper transport apparatus 900 also includes a drum motor 904 that rotates the photosensitive drum 901 and a paper transport motor 908 that transports the paper P (FIG. 8).

  The winding detection sensor 911, the HP sensor 913, the drum motor 907, the paper conveyance motor 908, and the winding detection sensor motor 912 are controlled by the control device (FIG. 8) of the paper conveyance device 900, respectively.

  FIG. 8 is a functional block diagram of the control device of the paper transport apparatus 900 of FIG.

  The control device 300 of the paper transport apparatus 100 includes a CPU 301, a ROM 302, a RAM 303, an input / output port (PIO) 304, an ASIC 305, and a motor driver 306, which are connected to each other via a system bus.

  The CPU 301 generally controls this apparatus. The ROM 302 stores the control program of the CPU 301, and the RAM 303 stores data temporarily stored in the control flow of the CPU 301, adjustment data unique to the apparatus, and the like.

  The PIO 304 inputs detection signals from the winding detection sensor 911 and the HP sensor 913. On the other hand, the ASIC 305 controls the drum motor 907, the paper transport motor 908, and the winding detection sensor motor 912 via the motor driver 306. However, the start timing and stop timing of each motor are controlled by instructions from the CPU 301.

  7 has the same configuration as that of the first embodiment as described above. Therefore, each process of FIGS. 4 to 6 can be executed, and the first embodiment can be executed. Has the same effect as.

  The present invention has a paper conveyance device having a photosensitive drum by an electrophotographic method and a fixing device for fixing toner on paper by a heat fixing method, and is mainly used for a printer, a copying machine, a FAX, a printing machine, and the like. Conceivable.

1 is a diagram schematically illustrating a configuration of a sheet transport device according to a first embodiment of the present invention. FIG. 2 is a functional block diagram of a control device of the paper transport apparatus 100 in FIG. 1. 3 is a flowchart illustrating a procedure of a wrapping detection sensor home position control process executed by the sheet conveying apparatus 100 of FIG. 1. 3 is a flowchart showing a procedure of a power-on winding control process executed by the paper conveyance processing apparatus of FIG. 1. 3 is a flowchart illustrating a procedure of a wrapping detection control process when fixing paper jam is stopped, which is executed by the paper transport device of FIG. 6 is a flowchart illustrating a procedure of paper jam processing required in step S205 of FIG. 4 or step S305 of FIG. It is a figure which shows schematically the structure of the paper conveying apparatus which concerns on the 2nd Embodiment of this invention. FIG. 8 is a functional block diagram of a control device of the paper transport apparatus 100 in FIG. 7. It is a figure which shows schematically the structure of the conventional paper conveying apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Paper conveying apparatus 101 Fixing roller 102 Pressure roller 103,913 Home position motor 104,914 Transport path 201,911 Roll detection sensor 202,912 Roll detection sensor motor 901 Photosensitive drum 902 Transfer roller

Claims (5)

In a paper transport device of an electrophotographic apparatus that transports paper along a transport path,
A pair of rollers provided in the transport path through which the paper passes;
A sheet that is provided upstream of the roller pair, is movable to a position in the conveyance path and a position outside the conveyance path, and moves to a position in the conveyance path to detect the presence or absence of a sheet in the conveyance path Detection means;
When a paper jam at the position of the roller pair is detected by a sensor that detects paper other than the paper detection means while the paper detection means is moved to a position outside the conveyance path , after stopping the said sheet sensing means is moved into the conveying path, when the paper detecting means does not detect a sheet, store abnormality that represents a service call by the sheet to the rollers is wound around And a service call, and when the paper detection means detects paper, a control means for requesting a paper jam removal process ;
Have a, said control means, said paper sensing means at the time of power-on of the electrophotographic apparatus is moved in the sheet conveying path, the sheet detection means abnormality is represented and the service call does not detect the paper And a paper transport device for an electrophotographic apparatus, characterized in that a service call is output . Wherein, said sheet when said detecting means in a state of being moved into the conveying path sheet detection means is detecting the sheet, the sheet sensing means and the conveying path outside for paper jam treatment by the user 2. The sheet conveying apparatus for an electrophotographic apparatus according to claim 1 , wherein the sheet conveying apparatus is moved to the position. The control means moves the paper detection means into the paper conveyance path when the electrophotographic apparatus is turned on, and the paper detection means does not detect the paper and the abnormality indicated by the service call is stored. 2. The electrophotographic apparatus according to claim 1, wherein fixing temperature adjustment control of the electrophotographic apparatus is performed, and a paper jam removal process is requested when the sheet detecting means detects the sheet . Paper transport device. 4. The sheet conveying device of an electrophotographic apparatus according to claim 1, wherein the pair of rollers is a pair of fixing rollers that heat-fix the unfixed toner transferred onto the sheet onto the sheet. 5. 4. The sheet conveying apparatus of an electrophotographic apparatus according to claim 1, wherein the roller pair is a pair of a photosensitive drum and a transfer roller that transfers toner to a sheet. 5.

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