JP2001146345A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide a paper meandering correcting means for preventing the short service life of a fixing roller without having influence on transfer performance and fixing performance and preventing adverse influence on a transfer belt and a fixing belt. SOLUTION: In this printer having an endlessly movably supported transfer belt 41 extended to a heating roller 14 and an idler roller 17, a photoreceptor 21 arranged oppositely to the transfer belt, a transfer means 10 being arranged on the back face side of the transfer belt and transferring a toner image formed on the photoreceptor to the transfer belt and a pressurizing roller 15 brought into pressure contact with the heating roller via the transfer belt and having an imaging unit for sandwiching/carrying a recording material 7 by a pressure contact part of the transfer belt and the pressurizing roller and transferring/ fixing the toner image formed on the transfer belt to the recording material, a meandering correcting means for correcting meandering of the recording material is provided in a recording material carrying directional downstream part to the pressure contact part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a printing apparatus for recording and forming a toner image on a recording material using an electrophotographic process.

[0002]

2. Description of the Related Art The prior art will be described with reference to FIGS. FIG. 7 shows a recording material 7 ( (Mainly a sheet) is shown. The heating roller 14 is rotated by a driving source (not shown) so as to convey the transfer belt 41 and the recording material 7 at a constant speed, and a temperature sensor (not shown).
Controls the surface at a constant temperature. The pressure roller 15 is pressed at a constant pressure against the heating roller 14 with the transfer belt 41 and the recording material 7 interposed therebetween by guides 27 and 28 supporting the pressure roller 15 at both ends.

The paper feeding mechanism 16 rotates at a speed higher than the recording material transport speed in the scuff roll 29, the pressing roll 30, and the scuff roll 29, which pinch and transport the recording material 7, and transfers the recording material 7 via the scuff roll 29. Drive shaft 31 for applying tension, drive motor 3 for drive shaft 31
2, a spring 3 for applying a pressing force to the pressing roll 30
3. A fixing plate 34 of a spring 33 is provided to discharge the recording material 7 while always applying a constant tension, thereby preventing the recording material 7 from winding around the heating / pressurizing roller or the transfer belt.

[0004] In the paper transport in the above-described configuration, a paper meandering problem often occurs due to paper shrinkage or the like. Therefore, conventionally, as shown in FIGS. 8, 9 and 10, guides 27 and 28 for supporting the pressure roller 15 at both ends are moved back and forth, so that the heating roller 1 of the pressure roller 15 is moved.
The meandering correction of the paper was performed by changing the pressing force to the paper 4 in the paper width direction.

[0005]

In the above-described prior art, the meandering correction of the sheet is performed in the transfer section and the fixing section to the sheet, so that the moisture content varies within the sheet and a difference in shrinkage occurs. When printing on easy-to-print paper, there is a problem that a biased load is always present between the heating roller and the pressure roller, and the transfer performance and the fixing performance vary in the paper width direction. In addition, the load on the heating roller and the pressure roller increased, and there was a problem with the short life of the roller. Furthermore, due to the uneven load between the heating roller and the pressure roller, the transfer belt and the fixing belt that are nipped and conveyed between these rollers meander, and the printing position shifts. There was a defect.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an inexpensive paper meandering correcting means which does not affect the transfer performance and the fixing performance, prevents the short life of the fixing roller, and prevents the transfer belt and the fixing belt from being adversely affected. An object of the present invention is to provide a printing apparatus that can be provided in a configuration.

[0007]

An object of the present invention is to provide a transfer belt supported by a heating roller and an idler roller and supported endlessly and movably, and a photosensitive member arranged opposite to the transfer belt. Disposed on the back side of the transfer belt,
A transfer unit configured to transfer a toner image formed on the photosensitive member to a transfer belt; and a pressing roller pressed against the heating roller via the transfer belt. And a printing unit for transferring and fixing the toner image formed on the transfer belt to the recording material while nipping and transporting the recording material in the transfer unit. Downstream,
This is achieved by providing a meandering correcting means for correcting the meandering of the recording material.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a recording material in which an unfixed toner image transferred to a transfer belt 41 in a previous process is nipped and conveyed together with the transfer belt 41 by a heating roller 14 and a pressure roller 15 having a heater 25 therein. FIG. 7 shows a mechanism for fixing simultaneously with transfer. The heating roller 14 is rotated by a driving source (not shown) so as to convey the transfer belt 41 and the recording material 7 at a constant speed, and the surface is controlled to a constant temperature by a temperature sensor (not shown). The pressure roller 15 is pressed at a constant pressure against the heating roller 14 with the transfer belt 41 and the recording material 7 interposed therebetween by guides 27 and 28 supporting the pressure roller 15 at both ends.

The paper feeding mechanism 16 rotates at a speed higher than the recording material transport speed in the scuff roll 29, the pressing roll 30, and the scuff roll 29 for nipping and transporting the recording material 7, and tensions the recording material 7 via the scuff roll 29. Shaft 31 for providing the drive, drive motor 3 of drive shaft 31
2, a spring 3 for applying a pressing force to the pressing roll 30
3. A spring fixing plate 35 that fixes the spring 33 and is rotatable around the center in the paper width direction, a motor 36 that rotates the spring fixing plate 35, pulleys 37, 38, and 39 that transmit the driving force of the motor 36; And a wire 40.
Here, the pressing roll 30 is divided into a plurality of rollers in the sheet width direction.

In the above configuration, when the recording material 7 meanders due to paper contraction or the like, the motor 36 rotates and the recording material 7
The spring fixing plate 35 is rotated so that the spring 33 in the direction of returning the spring to the original traveling position is extended. FIGS. 2 and 3 are schematic diagrams when the spring fixing plate 35 is rotated in both directions. 4, 5 and 6 show the pressure distribution of the pressing roll 30 when the spring fixing plate 35 is rotated. As shown in the figure, the spring 3 in the direction of returning the recording material 7 to the original traveling position
3 extends, the pressing roll 30 in the returning direction.
Of the recording material 7 is relatively increased, and the meandering of the recording material 7 is corrected. Since the pressing roll 30 is divided into a plurality of pieces in the sheet width direction, it is easy to relatively change the pressing force of the sheet in the width direction. The effect is further increased by dividing the scuff roll 29 into a plurality in the paper width direction in the same manner.

As a result, since the fixing of the recording material 7 and the meandering correction can be performed by different mechanisms, there is no uneven load between the heating roller and the pressing roller, and the transfer and the fixing of the toner to the recording material are uniform. It can be performed and the short life of the fixing roller can be prevented. Further, it does not affect the transfer belt transfer.

In this case, the pressing means is only one of the rotations of the spring fixing plate 35 by the motor 36, and the cost can be reduced.

FIG. 11 shows a full-color printing apparatus using the present invention. In FIG. 11, when the photosensitive drum 21 starts to rotate, a high voltage is applied to the corona charger 2 and the surface of the photosensitive drum 21 is uniformly charged with, for example, a positive charge.
When an exposure unit 1 such as a laser or an LED exposes the surface, an electrostatic latent image is formed. When the electrostatic latent image passes through the developing device 6, toner is supplied to the electrostatic latent image. A toner image is formed on the photosensitive drum 21. The toner image on the photosensitive drum 21 is transferred to the transfer belt 41 by the action of the transfer unit 10 that applies a charge having a polarity opposite to that of the toner image. By performing this transfer step four times, a full-color image is formed.

The transfer belt 41 includes a heating roller 14 for driving the belt and an idler roller 1 for applying tension to the belt.
7 and rotates at the same speed as the printing speed. At this time,
By pressing the pressure roller 15 against the heating roller 14, the recording material 7 is nipped and conveyed across the transfer belt 41, and is heated and pressed to thermally transfer and fix the toner image on the transfer belt 41 onto the recording material 7.

The meandering of the recording material 7 rotates at a speed higher than the recording material conveyance speed, and applies a tension to the recording material.
The correction is made by varying the tension difference between the recording roll 9 and the pressing roll 30 in the recording material width direction.

FIG. 12 shows a full-color duplex printing apparatus in which the printing mechanism shown in FIG. 11 is arranged on both sides of a recording material. Since both the front side printing and the back side printing have the driving force of the heating roller 14, the buffer 24 for absorbing the speed fluctuation of the recording material 7 is used.
Is arranged between the front side printing and the back side printing. Further, since both the front side printing and the back side printing have a heating source that generates meandering, both the scuff roll 29 and the pressing roll 30 are disposed at the subsequent stage of the transfer and fixing section to the recording material 7.

FIG. 13 shows an example of application in a full-color printing machine having a mechanism in which a heating roller 14 (a heating belt is also possible) is arranged between the transfer belt 41 and the recording material 7 to facilitate transfer belt cooling during high-speed printing. Is shown. FIG.
Is a full-color double-sided printing apparatus in which the printing mechanisms are arranged on both sides of a recording material.

[0019]

As described above, according to the present invention,
It is possible to provide, with an inexpensive configuration, a paper meandering correction unit that does not affect the transfer performance and the fixing performance, prevents the short life of the fixing roller, and prevents the transfer belt and the fixing belt from being adversely affected. A printing device can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a paper transport device of a fixing unit of a printing apparatus using the present invention.

FIG. 2 is a schematic diagram showing the operation of a paper transport device using the present invention.

FIG. 3 is a schematic diagram illustrating the operation of a paper transport device using the present invention.

FIG. 4 is a schematic diagram illustrating the operation principle of a paper transport device using the present invention.

FIG. 5 is a schematic diagram showing the operation principle of a paper transport device using the present invention.

FIG. 6 is a schematic diagram illustrating the operation principle of a paper transport device using the present invention.

FIG. 7 is a schematic diagram illustrating a conventional example of a fixing section paper transport device of a printing apparatus.

FIG. 8 is a schematic diagram illustrating the operation principle of a conventional example of a paper transport apparatus.

FIG. 9 is a schematic diagram illustrating the operation principle of a conventional example of a paper transport apparatus.

FIG. 10 is a schematic diagram illustrating the operation principle of a conventional example of a paper transport apparatus.

FIG. 11 is a schematic view showing a full-color printing apparatus using the present invention.

FIG. 12 is a schematic view showing a full-color duplex printing apparatus using the present invention.

FIG. 13 is a schematic view showing a full-color printing apparatus using the present invention.

FIG. 14 is a schematic diagram showing a full-color duplex printing apparatus using the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... laser, 2 ... charger, 6 ... developing machine, 7 ... recording material, 1
0: transfer machine, 14: heating roller, 15: pressure roller, 1
6: paper tension holding mechanism, 21: photosensitive drum, 25: heater lamp, 27, 28: guide, 29: scuff roll, 30: pressing roll, 31: drive shaft, 32
... Drive motor, 33 ... Spring, 35 ... Spring fixing plate, 36 ...
Motor, 37, 38, 39 ... pulley, 40 ... wire, 41
... Transfer belt.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H028 BA06 2H032 AA14 BA09 BA18 BA19 BA21 BA23 2H033 AA14 BA10 BB01 2H078 AA20 BB02 BB12 CC06 DD51 DD57 DD73 3F104 AA01 CA11

Claims (7)

[Claims] A transfer belt supported by a heating roller and an idler roller and supported endlessly; a photoreceptor disposed opposite to the transfer belt; and a rear surface of the transfer belt. A transfer unit that transfers a toner image formed on the photoconductor onto a transfer belt, and a pressure roller that is pressed against the heating roller via the transfer belt. In a printing apparatus having a printing unit for nipping and conveying a recording material at a pressure contact portion and transferring and fixing a toner image formed on the transfer belt to the recording material, the recording material is conveyed to the pressure contact portion. A printing apparatus comprising a meandering correcting means for correcting meandering of a recording material in a downstream portion in the direction. A transfer belt supported by a drive roller and an idler roller and supported endlessly; a photoreceptor disposed opposite to the transfer belt; and a rear surface of the transfer belt. Transfer means for transferring the toner image formed on the photoreceptor to a transfer belt, a heating roller provided in contact with the transfer belt, and passing the toner image formed on the transfer belt, A pressure roller pressed against the heating roller, the recording material is nipped and conveyed by a pressure contact portion between the heating roller and the pressure roller, and a toner image formed on the heating roller is transferred to the recording material. And a printing apparatus having a printing unit for performing fixing, in a downstream portion in the recording material conveying direction with respect to the press contact portion,
A printing apparatus, comprising: a meandering correcting means for correcting meandering of a recording material. 3. The meandering correcting means comprises roller feeding mechanisms pressed against each other, one of which is divided into a plurality of rollers in the width direction of the recording material,
3. The printing apparatus according to claim 1, further comprising a tension varying unit that varies the tension of each roller independently. 4. A transfer belt which is wound around a heating roller and an idler roller and supported so as to be movable endlessly, a photoreceptor arranged opposite to the transfer belt, and arranged on a back side of the transfer belt. A transfer unit that transfers a toner image formed on the photoconductor onto a transfer belt, and a pressure roller that is pressed against the heating roller via the transfer belt. A pressing unit for nipping and conveying the recording material, and a printing unit for surface printing for transferring and fixing the toner image formed on the transfer belt to the surface of the recording material, a heating unit and an idler roller. A transfer belt supported movably and endlessly, a photoconductor arranged opposite to the transfer belt, and a toner image formed on the photoconductor arranged on the back side of the transfer belt. A transfer unit for transferring to the transfer belt, and a pressure roller pressed against the heating roller via the transfer belt, while nipping and conveying the recording material at a pressure contact portion of the transfer belt and the pressure roller, A printing unit for transferring and fixing the toner image formed on the transfer belt to the back surface of the recording material, and a printing unit for printing on the back surface. A printing apparatus comprising a meandering correcting means for correcting meandering of a material. 5. A transfer belt supported by a drive roller and an idler roller and supported endlessly, a photoreceptor disposed opposite to the transfer belt, and a rear surface of the transfer belt. Transfer means for transferring the toner image formed on the photoreceptor to a transfer belt, a heating roller provided in contact with the transfer belt, and passing the toner image formed on the transfer belt, A pressure roller pressed against the heating roller, the recording material is nipped and conveyed by a pressure contact portion of the heating roller and the pressure roller, and a toner image formed on the heating roller is transferred to the surface of the recording material. A printing unit for surface printing that performs transfer and fixing, a transfer belt that is wrapped around a drive roller and an idler roller, and that is supported to be endlessly movable, and that is disposed to face the transfer belt. A photoreceptor, a transfer unit disposed on the back side of the transfer belt, for transferring a toner image formed on the photoreceptor to a transfer belt, and a transfer unit provided in contact with the transfer belt and formed on the transfer belt. A heating roller through which the formed toner image is transferred, and a pressure roller pressed against the heating roller, the recording material is nipped and conveyed by a pressure contact portion between the heating roller and the pressure roller, and the heating roller is A printing unit for transferring and fixing the toner image formed thereon to the back surface of the recording material, and a printing unit for printing on the back surface. Printers each provided with a meandering correction means for correcting the deviation. 6. The meandering correcting means comprises roller feeding mechanisms which are in pressure contact with each other, one of which is divided into a plurality of rollers in the width direction of the recording material,
6. The printing apparatus according to claim 4, further comprising a tension varying unit that varies the tension of each roller independently. 7. A recording medium conveying path between the printing unit for printing on the front side and the printing unit for printing on the back side, comprising buffer means for absorbing slack and tension of the recording material caused by a difference in conveying speed. The printing device according to claim 4 or 5, wherein