JP2007041370A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus devised to restrain continuous paper from being liable to be deformed. <P>SOLUTION: The image forming apparatus includes a paper conveying section having a consecutive conveyance mode by which continuous paper is consecutively conveyed to the downstream side of a conveyance path, a conveyance stop mode by which conveyance of continuous paper in a state inserted to the conveyance path is stopped, and a reciprocal movement mode by which the continuous paper is moved reciprocally on the conveyance path so as to avoid stationary contact of a specific part of the continuous paper with a specific member. The image forming apparatus also includes a mode switching control section by which the paper conveying section is switched to the consecutive conveyance mode when images are formed on the continuous paper and to the conveyance stop mode in response to the finish of the formation of the images on the continuous paper, and is switched to the reciprocal movement mode at any point in time when image formation is not carried out on the continuous paper. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that forms an image on continuous paper.

  2. Description of the Related Art Conventionally, there has been known an image forming apparatus such as a printer that forms a toner image and forms an image on the continuous paper by transferring and fixing the toner image on the continuous paper conveyed on a predetermined conveyance path. (For example, refer to Patent Document 1, Patent Document 2, and Patent Document 3).

In such an image forming apparatus that forms an image on continuous paper, a number of members such as rollers that sandwich the continuous paper or contact the continuous paper are provided along the conveyance path of the continuous paper.
JP 2004-252232 A JP 2004-184922 A JP 2003-263087 A

  However, in the above-described image forming apparatus, while the image is not being formed, the specific part of the continuous paper remains in contact with the specific member on the conveyance path in a stationary state, and the continuous paper has a deformation flaw and looks good. There is a problem of getting worse.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an image forming apparatus that is devised to prevent deformation of the continuous paper from being deformed.

In order to achieve the above object, an image forming apparatus of the present invention comprises:
In an image forming apparatus that forms a toner image and forms an image on the continuous paper by transferring and fixing the toner image on the continuous paper conveyed on a predetermined conveyance path.
To a specific member of a continuous conveyance mode in which continuous paper is continuously conveyed to the downstream side of the conveyance path, a conveyance pause mode in which the conveyance of the continuous paper inserted in the conveyance path is paused, and a specific part of the continuous paper A paper transport unit having a reciprocating mode in which the continuous paper is reciprocated on the transport path so as to avoid static contact of
The paper transport unit is switched to the continuous transport mode when an image is formed on continuous paper, and is switched to the transport stop mode upon completion of image formation on the continuous paper. And a mode switching control unit for switching to the reciprocating mode at the time of the above.

  In the image forming apparatus of the present invention, the mode is switched from the conveyance pause mode to the reciprocating mode at any time when the image is not formed on the continuous paper. Therefore, according to the image forming apparatus of the present invention, the stationary contact time of the specific part of the continuous paper to the specific member can be shortened as compared with the prior art, thereby suppressing the deformation of the continuous paper. be able to.

Here, it has a timer to measure time,
The mode switching control unit may switch to the reciprocating movement mode when a predetermined time has elapsed since switching from the continuous paper transport mode to the transport pause mode.

In addition, it has a temperature sensor that measures temperature,
The mode switching control unit is preferably configured to switch to the conveyance suspension mode in response to the temperature falling below a predetermined temperature when in the reciprocating movement mode.

  Compared with the case where the temperature of the specific member that is in contact with the specific part of the continuous paper 100 is high, the deformation flaw is weak when the temperature of the specific member is low. When the temperature drops below, it is considered that the temperature of the specific member is low, and the mode is switched from the reciprocating mode to the conveyance pause mode, so that the continuous paper can be effectively prevented from being deformed.

  According to the image forming apparatus of the present invention, it is possible to prevent the continuous paper from being deformed.

  Hereinafter, embodiments of the image forming apparatus of the present invention will be described.

  FIG. 1 is a detailed configuration diagram of the printer of this embodiment.

  The printer 1 shown in FIG. 1 includes an image forming unit 10 from the upper right side to the upper central side, a control unit 11 at the lower right side, a paper hopper unit 12 that stores continuous paper at the lower center, and a drive roller at the upper left side. Part 14, scuff roller part 13 upstream of the drive path from drive roller part 14, sheet stacker part 15 at the left middle stage, back tension part 16 at the middle middle stage, and an apposition disposed above back tension part 16 The lining unit 17, the subtractor unit 18, the tractor unit 19, and a number of other rotating rollers arranged along the conveyance path are used as components.

  The detailed description of the image forming unit 10 is omitted since it is a well-known technique, but it is composed of a charger, an exposure unit, a developing unit provided at the upper right side in FIG. Has been. The control unit 11 controls the entire printer.

  The paper hopper unit 12 can store continuous paper with pages connected and sprocket holes formed at both ends of the paper. The paper stacker unit 15 is supplied from the paper hopper unit 12 to form an image. The continuous paper on which image formation in the section 10 has been completed is collected.

  In addition, as shown in FIG. 1, the printer 1 can form an image on continuous paper supplied from a pre-processing device or the like that stores continuous paper. FIG. 1 shows a continuous image supplied from outside the printer. An image is formed on the paper 100, and the state where the continuous paper 100 after the image formation is discharged to the outside of the printer is shown.

  Here, an image forming operation for the continuous paper 100 supplied from outside the printer in the printer 1 will be described.

  The continuous paper 100 supplied from the outside of the printer passes through the back tension unit 16 and the aligning unit 17 and is sent out of the printer when printing in the image forming unit 10 is completed. In the drive roller unit 13, the continuous paper 100 is strongly nipped as compared to the back tension unit 16, thereby preventing slippage. Thus, in the printer 1, the drive roller 14 a provided in the drive roller unit 14 is prevented. The accuracy of the printing position on the continuous paper is ensured by controlling the rotation of the paper. Further, the tension between the portions of the continuous paper 100 between the scuff roller portion 13 and the back tension portion 16 is ensured by the rollers disposed on the continuous paper 100 slipping on the continuous paper. The aligning unit 17 adjusts the position of the continuous paper 100 on the near side and the far side in FIG. Further, during image formation on continuous paper having no sprocket holes, the subtractor unit 18 and the tractor unit 19 are retracted from the conveyance path.

  Next, a case where printing is performed on continuous paper accommodated in the paper hopper portion 12 and having sprocket holes formed therein will be described.

  In this case, the continuous paper is transported in a state where the sprocket holes of the continuous paper are engaged with the sprockets provided in the subtractor unit 17 and the tractor unit 18, and the continuous paper transported through the transport path is: After the printing in the image forming unit 10 is completed, it is accommodated in the paper stacker unit 15.

  Next, a description will be given of the operation of conveying the continuous paper supplied from the outside of the printer in the printer 1 of this embodiment when image formation is performed intermittently.

  The printer 1 pauses the continuous transport mode, which is the transport mode of the continuous paper 100 when printing on the continuous paper 100 is continuously performed, and the transport of the continuous paper 100 inserted on the transport path. And a reciprocation mode in which a specific part of the continuous paper 100 is reciprocated on the conveyance path so as to avoid stationary contact with a specific member. As will be described later, the control unit 11 controls the temperature of the drive roller 14a provided in the drive roller unit 14 and the time from when the mode is switched to the conveyance suspension mode.

  FIG. 2 is an enlarged schematic view of a part of the printer shown in FIG.

  In FIG. 2, the control unit 11 shown in FIG. 1 has a timer 11a that measures the time from when the mode is switched to the conveyance suspension mode, and the rotational speed of the drive roller 14a and the roller of the back tension unit The state of being connected to a temperature sensor 14b that controls the rotational speed of 16a and detects the temperature in the vicinity of the drive roller 14a is shown.

  In the printer 1, the continuous paper 100 supplied from outside the printer is conveyed by controlling the rotational speeds of both the drive roller 14 a of the drive roller unit 14 and the roller 16 a of the back tension unit 16. .

  FIG. 3 is a time chart showing how the rotational speeds of the drive roller and the back tension roller are controlled.

  FIG. 3A shows a change in the rotational speed of the drive roller 14a, with the horizontal axis representing time elapsed and the vertical axis representing the rotational speed of the drive roller 14a. In FIG. 3B, the horizontal axis represents time. The change in the rotational speed of the back tension roller 16a is shown with the lapse of time and the vertical axis as the rotational speed of the back tension roller 16a.

  In FIG. 3, the rotational speeds of the drive roller 14a and the back tension roller 16a are constant until slightly beyond the “end of transfer”, and the rotational speed of the drive roller 14a is higher than the rotational speed of the back tension roller 16a. It is shown that it is set too high. As described above, since the drive roller 14a does not slip, the back tension roller 16a slips, and continuous tension toward the downstream side of the transport path is ensured while securing the tension of the portion of the continuous paper 100 located between these rollers. Transport is performed with high accuracy. Thereafter, the back tension roller 16a starts decelerating first, and the drive roller 14a starts decelerating after a delay. This is to maintain the tension of the portion located between these rollers even during this deceleration. After the rotation of both rollers stops, reverse conveyance of the continuous paper 100 toward the upstream side of the conveyance path is performed in order to recover the amount of overfeed from the start of deceleration to the stop of rotation. In order to secure the tension between these rollers, the rotation of the back tension roller 16a is started first, and the rotation is stopped behind the drive roller 14a. As a result, when the current “printing end”, that is, the active mode ends, the printer 1 switches to the stop mode until the start of printing based on the next data. In this printer 1, a predetermined time elapses after entering the stop mode. Then, the mode is switched to the semi-active mode.

  The semi-active mode is a mode in which a continuous portion of the continuous paper 100 is reciprocally moved on the conveyance path so as to avoid a stationary contact with a specific member. As a result, the continuous paper 100 is deformed. Can be suppressed.

  As shown in FIG. 3, in the semi-active mode, the continuous paper 100 is reciprocated to the downstream side and the upstream side of the conveyance path as one set, and the drive roller 14a and back tension at this time are conveyed. The rotation start timing and rotation stop timing of the roller 16a are also controlled so as to ensure the tension of the portion of the continuous paper 100 between these rollers.

  In addition, when the printer 1 is in the semi-active mode, the semi-active mode is switched to the stop mode when the temperature measured by the temperature sensor 14b disposed in the vicinity of the drive roller 14a shown in FIG. It is done. This is because even if the specific part of the continuous paper 100 comes into contact with the specific member in a stationary state, the specific member is less affected if the temperature of the specific member is low. Note that the printer 1 suppresses the formation of a blank paper portion on the continuous paper by reverse transport in the active mode or mode switching after the end of setting in the semi-active mode. Further, in the above embodiment, when the measured temperature falls below the predetermined temperature when in the semi-active mode, the mode is switched from the semi-active mode to the stop mode. Even if the measured temperature exceeds the predetermined temperature, the print instruction Is issued, the mode is switched from the semi-active mode to the active mode after the setting is completed.

  FIG. 4 is a flowchart of a routine that is started when the print power is turned on according to this embodiment.

  In step S1 shown in FIG. 4, the stop mode is selected as the initial mode, and in step S2, it is determined whether there is a print instruction. If it is determined in step S2 that there is an instruction, the process proceeds to step S11. If it is determined that there is no instruction yet, the process proceeds to step S3, and the mode is switched to the stop mode. In step S4, the timer is turned on, and in step S5, it is determined whether a predetermined time set in advance has elapsed. If it is determined in step S5 that the time has not elapsed, the process returns to step S2. If it is determined that the time has elapsed, the process proceeds to step S6, and the timer is turned off. In step S7, the mode is switched from the stop mode to the semi-active mode. In step S8, the temperature near the drive roller 16a is detected. In step S9, it is determined whether or not the detected temperature is equal to or lower than a predetermined temperature set in advance. If it is determined in step S9 that the temperature is equal to or lower than the predetermined temperature, the process returns to step S2, thereby canceling the semi-active mode. If it is determined in step S9 that the temperature exceeds the predetermined temperature, the process proceeds to step S10, and it is determined whether or not there is an instruction to start printing. If it is determined in step S10 that there is no instruction, the process returns to step S7. If it is determined in step S10 that there is an instruction, the process proceeds to step S11, and the mode is switched to the active mode. In step S12, it is determined whether printing has been completed. If it is determined in step S12 that printing has not yet been completed, step S12 is repeated, and if it is determined that printing has been completed, processing returns to step S2.

  As described above, in the printer 1 of the present embodiment, the mode is switched from the stop mode to the semi-active mode after a predetermined time has elapsed since the switching to the stop mode. The stationary contact time with the specific member can be shortened compared to the conventional case. Therefore, according to the printer 1 of the present embodiment, the continuous paper 100 can be prevented from being deformed.

  In addition, the printer 1 according to the present embodiment is less susceptible to deformation wrinkles when the temperature of the specific member is low than when the temperature of the specific member that is in contact with the specific portion of the continuous paper 100 is stationary. Even when the mode is switched to the semi-active mode, the mode is switched from the semi-active mode to the stop mode when the temperature detected by the temperature sensor 14b provided in the vicinity of the drive roller 14a becomes a predetermined temperature or lower. Thus, it is possible to effectively suppress the deformation of the continuous paper 100.

  In the above-described embodiment, the example in which the mode is switched to the semi-active mode based on the passage of time from the time when the mode is switched to the stop mode has been described. However, the present invention is not limited to this. Instead, it is only necessary to switch to the semi-active mode at any point in time when the image is not formed on the continuous paper.

  Further, in the embodiment described above, the case where mode switching is performed based on the temperature obtained by the temperature sensor 14b provided in the vicinity of the drive roller 14a is taken as an example, but the arrangement position of the temperature sensor is limited to this. Further, the continuous paper 100 supplied from the outside of the printer is typically taken up and described. However, by controlling the tractor unit 19 instead of the drive roller 14a, in the present invention, this is a paper hopper. The continuous paper which was accommodated in the part 12 and in which the sprocket hole was drilled may be used.

1 is a detailed configuration diagram of a printer according to an embodiment. FIG. 2 is an enlarged schematic view of a part of the printer shown in FIG. 1. It is a time chart which shows the mode of control of the rotational speed of a drive roller and a back tension roller. 4 is a flowchart of a routine that is started when a print is turned on according to the present exemplary embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer 10 Image forming part 11 Control part 12 Paper hopper part 13 Scuff roller part 14 Drive roller part 15 Paper stacker part 16 Back tension part 17 Aligning part 18 Subtractor part 19 Tractor part

Claims (3)

In an image forming apparatus that forms a toner image and forms an image on the continuous paper by transferring and fixing the toner image on the continuous paper conveyed on a predetermined conveyance path.
To a specific member of a continuous conveyance mode in which continuous paper is continuously conveyed to the downstream side of the conveyance path, a conveyance pause mode in which the conveyance of the continuous paper inserted in the conveyance path is paused, and a specific part of the continuous paper A paper transport unit having a reciprocating mode in which the continuous paper is reciprocated on the transport path so as to avoid static contact of
When the image is formed on the continuous paper, the paper transport unit is switched to the continuous transport mode, is switched to the transport pause mode upon completion of image formation on the continuous paper, and is not formed when the image is not formed on the continuous paper. An image forming apparatus comprising: a mode switching control unit that switches to the reciprocating mode at the point of time. With a timer that measures time,
The image forming apparatus according to claim 1, wherein the mode switching control unit switches to the reciprocating movement mode when a predetermined time has elapsed since switching from the continuous paper conveyance mode to the conveyance suspension mode. apparatus. Equipped with a temperature sensor to measure the temperature,
The mode switching control unit switches to the conveyance suspension mode in response to the temperature falling below a predetermined temperature when in the reciprocating movement mode. Image forming apparatus.

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