JP4796528B2 - Paper transport control method and electrophotographic apparatus - Google Patents

Description

  The present invention relates to paper conveyance control in a paper conveyance mechanism of an electrophotographic apparatus such as a laser beam printer or a copying machine.

  In an electrophotographic apparatus such as a laser beam printer, as shown in FIG. 4, the printing paper 201 is moved by the tractor 203 at the same speed as the cycle of the photosensitive drum 202, and toner (not shown) is transferred to the printing paper 201 by the transfer device 208. Then, after passing through the buffer 204 for applying a constant tension to the printing paper 201, passing through the paper transport guide 205, a heat roll 206 and a pressure roll 207 pressurize and heat a toner image (not shown), After the printing paper 201 is melted and fixed on the printing paper 201, the printing paper 201 is pulled with a constant tension by the puller 210, the printing paper 201 is folded by the swing fin 212 for folding the printing paper 201, and then the printing paper 201 is fed to the stacker 213 on which the printing paper 201 is stacked. Transport.

  During non-printing, the printing paper 201 is in a stopped state, and the thermal roll 206 and the pressure roll 207 are in a non-contact state in order to prevent discoloration or deformation of the paper due to contact between the printing paper 201 and the thermal roll 206. Since the sheet 201 remains in the state when printing is stopped, there is no slack between the tractor 203 and the puller 210.

  Next, the operation of the puller 210 during printing will be described with reference to FIG.

  As shown in FIG. 2, the electrophotographic apparatus starts printing when the print signal PRINT-P from the host apparatus (not shown) becomes “1”, and stops printing when PRINT-P becomes “0”. When PRINT-P becomes “1”, the puller driving signal PULLER DRV-P signal is set to “1”, the puller direction signal PULLER CCW-P is set to “1”, and the puller driving unit 211 causes the puller 210 to rotate in the paper transport direction. . When the print signal PRINT-P from the host apparatus becomes “0”, the drive signal PULLER DRV-P signal of the puller 210 is set to “0”, and the puller 210 stops.

  Next, the operation of the puller 210 during the operation of the stacker 213 will be described with reference to FIG. The stacker 213 can be raised and lowered by a stacker up / down switch 215 so that an operator can easily take out the printing paper 201 after printing is completed.

  As shown in FIG. 3, when the stacker switch pressing signal ST SW-P becomes “1” by pressing the stacker up / down switch 215, the stacker driving signal ST DRV-P is set to “1”, and the stacker driving unit 214 operates the stacker 213. . In order to prevent the heat roll 206 and the printing paper 201 from coming into contact with each other when the operator takes out the printing paper 201, the stacker switch press signal ST SW-P becomes “1”, so that the driving signal PULLER DRV of the puller 210 is set. The −P signal is set to “1”, the puller direction signal PULLER CCW-P is set to “1”, and the puller driving unit 211 drives the puller 210 in the paper transport direction. As a result, the paper is not loose between the tractor 203 and the puller 210 during the operation of the stacker 213.

  Further, in the case of a mechanism that can open and close the conveyance unit 216 when paper is loaded as in Patent Document 1, the puller 210 is driven even when the conveyance unit 216 is opened and closed so that there is no looseness between the tractor 203 and the puller 210. Yes.

Japanese Patent No. 3617217

  In the conventional electrophotographic apparatus, in order to prevent discoloration or deformation of the paper due to the contact between the heat roll 206 and the printing paper 201 during non-printing, the puller 210 is driven by the operation of the operator, and the tractor 203 and the puller 210 are driven. There was no slack in the paper. However, when the operator takes out the printing paper 201 from the stacker 203 without taking the stacker 203 up and down, there is no opportunity to drive the puller 210, so the paper is loose between the tractor 203 and the puller 210. In some cases, the sheet is deformed by the heat of the heat roll 206.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a highly reliable paper transport control method that eliminates problems caused by paper slack in a non-printing apparatus.

  In order to achieve the above object, the present invention provides a transfer device for transferring a toner image formed on a photoreceptor onto a paper, a paper transport tractor provided on the downstream side of the transfer device in the paper transport direction, A heat roll and a pressure roll that are provided on the downstream side in the paper transport direction and are fixed by heating and pressurizing the toner image transferred onto the paper, and a downstream side in the paper transport direction of the heat roll and the pressure roll. Paper transport of an electrophotographic apparatus that prints a toner image on the paper while transporting a continuous paper in a long length by the transport roller pair provided on the paper, the paper transport tractor, the heat roll, the pressure roll, and the transport roller pair In the control method, the conveyance roller pair is driven and stopped in the sheet conveyance direction at a predetermined interval when the sheet is stopped during non-printing.

  The paper transport control method of the present invention can eliminate the slack of the paper in the non-printing apparatus regardless of the operation of the operator, and can prevent thermal deformation and discoloration due to the hot roll contact of the paper.

  The purpose of preventing paper discoloration or deformation due to paper slack in the machine during non-printing and causing paper discoloration or deformation is the same as before by driving the puller in the paper transport direction at specified intervals. Realized by configuration.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a time chart showing a paper conveyance control method according to the present invention.

  When the print signal PRINT-P from the host device (not shown) becomes “1”, the electrophotographic apparatus sets the puller driving signal PULLER DRV-P to “1”, the puller direction signal PULLER CCW-P to “1”, and puller driving The puller 210 is driven in the paper transport direction by the unit 211. When PRINT-P becomes “0”, the driving signal PULLER DRV-P signal of the puller 210 is set to “0”, and the puller 210 stops. During the period when the PRINT-P signal is “0”, the printing paper 201 is in a non-printing state. During non-printing, the puller drive signal PULLER DRV-P signal is set to “0”, and after a lapse of T1, the puller drive signal PULLER DRV-P signal is set to “1”, the puller direction signal PULLER CCW-P is set to “1”, and T2 After a lapse of time, the puller driving signal PULLER DRV-P signal is set to “0”. Accordingly, the puller 210 is intermittently operated by repeatedly stopping for T1 time and driving for T2 time, and the slack of the paper between the tractor 203 and the puller 210 can be eliminated. The stop time T1 is set to a time that is short enough to prevent thermal deformation and discoloration due to heating of the printing paper 201 in the case where the printing paper 201 and the heat roll 206 are in contact.

  As described above, during non-printing, the puller 210 is driven in the paper transport direction at a predetermined interval, and the paper sag between the tractor 203 and the puller 210 causes the print paper 201 and the heat roll 206 to contact each other. Thus, thermal deformation and discoloration of the paper due to heating of the printing paper 201 can be prevented.

6 is a time chart illustrating a paper conveyance control method according to the present invention. It is a time chart which shows the conventional paper conveyance control method. It is a time chart which shows the conventional paper conveyance control method. 1 is a schematic configuration diagram of an electrophotographic apparatus.

Explanation of symbols

  201, printing paper, 202, photosensitive drum, 203, tractor, 204, buffer, 205, paper conveyance guide, 206, heat roll, 207, pressure roll, 208, transfer device, 210, puller, 211, puller drive unit, 212 is a swing fin, 213 is a stacker, 214 is a stacker drive unit, 215 is a stacker up / down switch, and 216 is a transport unit.

Claims (2)

A transfer device for transferring the toner image formed on the photosensitive member to the paper, a paper transport tractor provided downstream of the transfer device in the paper transport direction, and provided downstream of the tractor in the paper transport direction; A heat roll and a pressure roll for fixing the toner image transferred on the paper by heating and pressing; a pair of transport rollers provided on the downstream side of the heat roll and the pressure roll in the paper transport direction; and In a paper conveyance control method of an electrophotographic apparatus that prints a toner image on a sheet while conveying a long continuous sheet of paper by using a sheet conveyance tractor, the heat roll, a pressure roll, and a conveyance roller pair, stopping the sheet during non-printing sometimes driven at a specified interval the pair of conveying rollers to the paper transport direction, is stopped, the time of the stop, that the paper is shorter than the time that heat deformation by being heated by the heat roll Sheet transport controlling method of an electrophotographic apparatus according to symptoms. A transfer device for transferring the toner image formed on the photosensitive member to the paper, a paper transport tractor provided downstream of the transfer device in the paper transport direction, and provided downstream of the tractor in the paper transport direction; A heat roll and a pressure roll for fixing the toner image transferred on the paper by heating and pressing; a pair of transport rollers provided on the downstream side of the heat roll and the pressure roll in the paper transport direction; and defining the paper conveying tractor, the heat roll and the pressure roll and the transport roller pair Oite electrophotographic equipment for printing a toner image on the paper while conveying the continuous sheet to the long, when the paper stop in the non-printing driving the conveying roller pair spacing the sheet conveying direction, stopping, electrophotographic the time of the stop, characterized in that the paper is shorter than the time you heat deformation by being heated by the heat roll Location.

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