JPH11193143A - Carrier device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carrier device capable of suppressing positional deviation of a carrier belt and performing an exact and stable conveyance and an image forming device which is provided with this carrier device and is capable of forming a high grade image. SOLUTION: In a carrier device winding an endless carrier belt 1 around at least two roller members and driving the belt 1, sensors 7, 8 (detection means) detecting an axial location of the carrier belt 1, a roller 4 (correction means) for meandering adjustment correcting the axial location of the carrier belt 1 and a controller 9 (control means) determining a positional deviation amount based on the location detected by the sensors 7, 8 and controlling a correction amount of the carrier belt 1 by the roller 4 for meandering adjustment are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a conveying device for conveying an article such as a sheet material using an endless conveying belt, and an image forming apparatus provided with the conveying device.

[0002]

2. Description of the Related Art Conventionally, in a conveying apparatus which drives an endless conveying belt by winding it around two or more rollers, the rollers are not cylindrical in order to suppress meandering of the conveying belt.
A configuration in which the conveyor belt is self-aligned toward the center in the axial direction of the roller (the maximum diameter portion of the Tyco) by adopting a Tyco shape is adopted.

[0003]

However, in the above-mentioned prior art, since the rollers are formed in a drum shape instead of a cylindrical shape, the feed amount of the belt is different between the center portion and both end portions, so that precise conveyance is difficult. There was a problem.

In particular, in an image forming apparatus for forming an image on a sheet material, for example, a sheet material carrying a toner image is placed on a transport belt and transported to the next step (fixing step or backside image forming step). A plurality of image forming units (each forming a toner image of a different color) are arranged on a conveying belt, and the sheet material is sequentially conveyed to the plurality of image forming units while being placed on the conveying belt. The transport belt is employed in a configuration for forming a multicolor image by using the same.

[0005] However, in the case of a Tyco-shaped roller, the tension at the end of the conveyor belt may be weakened or the conveyance surface may not be flat. Due to problems such as the meandering of the conveyor belt, accurate and stable conveyance is required to maintain and improve image forming quality.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. It is an object of the present invention to suppress a displacement of a conveyor belt and to perform an accurate and stable conveyance. It is another object of the present invention to provide an image forming apparatus including the transport device and capable of forming a high-quality image.

[0007]

In order to achieve the above object, according to the present invention, at least two endless transport belts are provided.
Detecting means for detecting an axial position of the transport belt, a correcting means for correcting the axial position of the transport belt, and a detecting means for detecting the axial position of the transport belt. And control means for calculating a displacement amount based on the position and controlling a correction amount of the transport belt by the correction means.

[0008] The control means may determine that the position of the belt at the axial position of the conveyor belt detected by the detection means is one.
It is also preferable to obtain the amount of positional deviation using an averaged value during the period of the rotation.

Further, the control means obtains the axial position of the conveyor belt detected by the detection means with respect to a plurality of divided periods in a period in which the belt makes one revolution, and obtains the position at least one cycle before. It is also preferable to compare the obtained position information with the position information newly obtained in the corresponding period to determine the axial displacement amount of the transport belt.

[0010] The detecting means may detect a position of an end of the conveyor belt.

[0011] An image forming apparatus is characterized by comprising the above-described conveying apparatus and image forming means for forming an image on a sheet material conveyed by the conveying apparatus.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) FIG. 1 is a view showing the schematic arrangement of a conveying device SF1 for explaining the features of the present invention. In FIG. 1, 1 is a conveying belt, and 2 is a belt driving device. The driving rollers 3 are driven rollers for driving the belt.

Reference numeral 4 denotes a belt meandering adjustment roller, one end of which is supported by an actuator 6 as a correcting means so as to be vertically moved in the drawing.

Reference numeral 5 denotes a motor for driving the driving roller 2;
Reference numeral 8 denotes a sensor as detection means for detecting the end position of the conveyor belt 1, and reference numeral 9 denotes a controller as control means for adjusting the actuator 6.

Next, the operation of the above configuration will be described. The transport belt 1 is hung around a driving roller 2, a driven roller 3 and a meandering adjustment roller 4, and is driven by a driving motor 5 driving the driving roller 2.

The meandering adjustment roller 4 can be moved up and down by an actuator 6 to adjust the position of the transport belt 1 in the axial direction (meandering adjustment). The sensors 7 and 8 detect the movement of the end portion of the conveyor belt 1 in the axial direction,
The controller 9 that performs the meandering adjustment operates the actuator 6 based on the detection result.

Next, the operation of the controller 9 for adjusting the meandering will be described with reference to FIG. The movement of the conveyor belt 1 in the axial direction is detected by sensors 7 and 8 in the direction and amount of movement, and transmitted to a controller 9 as meandering information of the belt.

The controller 9 has a CPU 201 which is a ROM
In accordance with the above-described meandering correction program written in 202, a positional deviation amount and a corresponding correction amount are obtained, and the actuator 6 is operated to perform meandering correction.

Here, the sensor input I / F 204 (I / F:
The movement amount and direction of the transport belt 1 in the axial direction are taken into the CPU 201 by the interface. CPU2
01 outputs a command to drive the actuator 6 to the motor driver 205 according to the meandering correction program in order to cancel the movement of the belt in the axial direction.

The actuator 6 moves the meandering correction roller 4 in the vertical direction to perform meandering correction.

Next, the algorithm of the meandering correction program will be described. The CPU 201 outputs signals from the sensors 7 and 8 for detecting the end position of the conveyor belt to a sensor input I / F.
Take in via 204. The end position of the conveyor belt 1 is determined from the received signal.

The CPU 201 compares the end position data of the conveyor belt 1 with the reference position data prepared in advance to determine in which direction the conveyor belt 1 is displaced and the amount of deviation. Can be.

Based on this information, the CPU 201 can correct the meandering of the conveyor belt 1 by driving the actuator 6 via the motor driver 205. At this time, the actuator 6 is driven by a relative movement by a predetermined amount from the current position.

If meandering cannot be completely corrected by a single correcting operation, more accurate meandering correction can be performed by performing the correcting operation every time the feed amount of the conveyor belt 1 reaches a constant value.

In this embodiment, the configuration in which the actuator 6 is connected to the meandering adjusting roller 4 is shown as an example in the present embodiment. However, the present invention is not limited to this configuration. Even in a configuration in which the parallelism with respect to the driving roller 2 is adjusted, it is possible to adjust the positional deviation of the transport belt 1.

(Embodiment 2) The CPU 201 detects the position of the end of the conveyor belt 1 by taking in the signals from the sensors 7 and 8 via the sensor input I / F 204. Is not a straight line with high accuracy, the signal from the sensors 7 and 8 detects a value in which the meandering occurs even if the conveyor belt 1 does not meander.

Therefore, if this signal is used as it is, a correct meandering correction operation may not be performed. Therefore,
The meandering correction operation can be performed by regarding the signals from the sensors 7 and 8 averaged over one period of the conveyor belt 1 as the position of the conveyor belt 1.

(Embodiment 3) In the method of Embodiment 2, the meandering correction operation is performed by averaging the signals from the sensors 7 and 8 over a period of one round of the conveyor belt 1, so that the delay in the meandering correction operation is delayed. Can occur.

Therefore, the period of one round of the conveyor belt 1 is divided into a plurality of sections, the detection values for each section are obtained by the sensors 7 and 8, and the detection values one cycle before the belt are stored. By comparing the current detection value with the corresponding value, a quick meandering correction operation can be performed even when the end of the conveyor belt 1 is not a straight line with high accuracy.

In this case, the detection values of the sensors 7 and 8 detected in each of a plurality of sections can be used as they are, or can be averaged and used.

(Embodiment 4) Referring to FIG. 3, an example of an image forming apparatus using the transport device SF1 configured as described above will be described. Copier 10 as this image forming apparatus
Reference numeral 0 includes a reader unit A (image reading unit) for reading an image of the document G at an upper part, and a printer unit B (image forming means) for forming image information of the read document G on a sheet material S below the reader unit A. ing.

In the reader section A, the original G placed on the original glass is illuminated by a lamp 102 on a scanning table 101 which moves relatively to the original G in the sub-scanning direction. The light reflected from the original G is transmitted to a line image sensor (C) by an optical system 103 including a lens and a mirror.
The document G is irradiated to an image reading unit 104 having a CD sensor) and scanned in a main scanning direction and a sub-scanning direction.
The entire image information is read.

The image signal output from the image reading unit 104 after A / D conversion is output to the printer unit B.
The laser light is converted by the laser driver 105 into laser light L emitted from the laser light source 106.

The laser light L output from the laser light source 106 is applied to the polygon mirror 107 and the mirror 10.
The light is reflected and guided by the photosensitive drum 8, and scans the photosensitive drum 109 as an image carrier.

The photosensitive drum 109 rotates in the direction of the arrow shown in the figure, is uniformly discharged by the pre-exposure lamp 110, is uniformly charged by the primary charger 111, and is scanned by the laser beam L. An electrostatic latent image is formed on the surface.

The laser beam L is applied to the photosensitive drum 1 in a direction substantially parallel to the rotation axis of the photosensitive drum 109 (main scanning direction).
09, and an electrostatic latent image is formed by repeatedly scanning the photosensitive drum 109 in the rotation direction (sub-scanning direction) of the photosensitive drum 109.

The electrostatic latent image formed on the photosensitive drum 109 is visualized (developed: hereinafter referred to as a toner image) by the developing device 112.

On the other hand, the sheet material S is separated and fed from the sheet feeding cassette 120 or 121 on which a large number of sheet materials S are placed to the transport path H1 by separating sheet feeding rollers 120a and 121a in accordance with the image forming timing. Sent. In the transport path H1, the registration roller pair 122 corrects the attitude of the sheet material S and adjusts the sheet feeding timing, and transfers the sheet material S to the transfer area at the timing when the toner image formed on the photosensitive drum 109 is transferred to a predetermined position. Enter J. Reference numeral 123 denotes a transfer and separation charging device. The surface of the photoconductor drum 109 is cleaned by a cleaner 126 to remove adhered foreign substances such as toner.

The sheet material S to which the toner image has been transferred is separated from the photosensitive drum 109, placed and transported on the transport belt 1 of the transport device SF1, enters the fixing device 125, and the toner image is fixed. The sheet is discharged out of the apparatus (sheet discharge tray 127).

H2 is a switch turn path for reversing the image forming surface downward, and H3 is a reversing path for forming an image on the back surface. Reference numeral 128 denotes a manual tray for performing manual paper feeding.

Therefore, the conveyor belt 1 to which the present invention is applied
In the sheet material S, displacement and meandering in the axial direction are suppressed, and the sheet material S
Can be transported accurately and stably.

In the multicolor image forming apparatus, a plurality of image forming units are provided so as to be opposed to the conveying belt 1 of the conveying device SF1, and the sheet material S is conveyed by the conveying belt 1 in which the displacement is suppressed. In addition, it is possible to form a high-quality image with little deviation of sequentially formed images.

Further, the configuration of the transport device SF1 can be applied to an image forming apparatus configured to directly carry a toner image on the surface of the transport belt 1.

[0044]

As described in the embodiment of the present invention, a transport device capable of suppressing a positional deviation of a transport belt and capable of performing accurate and stable transport, and having the transport device and having a high quality Thus, an image forming apparatus capable of forming a stable image is obtained.

By using the axial position of the conveyor belt averaged during the period of one rotation of the belt, an accurate positional shift amount can be obtained regardless of the state of the end of the conveyor belt. Correct correction is performed based on the correction.

The position of the transport belt in the axial direction is determined for a plurality of divided periods in a period in which the belt makes one rotation, and the amount of positional deviation of the transport belt in the axial direction is determined based on the obtained position. Can do it.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of a transport device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a controller.

FIG. 3 is a diagram of an image forming apparatus to which the transport device according to the embodiment of the present invention is applied.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 conveyance belt 2 drive roller 3 driven roller 4 meandering adjustment roller 5 drive motor 6 actuator (correction means) 7, 8 sensor (detection means) 9 controller (control means)

Claims (5)

[Claims] 1. A conveying device for driving an endless conveyor belt around at least two roller members to drive the conveyor belt, wherein: a detector for detecting an axial position of the conveyor belt; and correcting the axial position of the conveyor belt. And a control unit that obtains a displacement amount based on the position detected by the detection unit and controls a correction amount of the transport belt by the correction unit. 2. The method according to claim 1, wherein the control unit calculates a position shift amount using an average of a position of the conveyance belt in the axial direction detected by the detection unit during a period in which the belt makes one rotation. The transfer device according to claim 1. 3. The control means obtains an axial position of the conveyor belt detected by the detection means for a plurality of divided periods in a period in which the belt makes one revolution, and obtains the position at least one cycle before. The transport apparatus according to claim 1, wherein the obtained positional information is compared with positional information newly obtained in a corresponding period to determine an axial displacement amount of the transport belt. 4. The transporting apparatus according to claim 1, wherein the detecting unit detects a position of an end of the transport belt. 5. An image, comprising: the conveying device according to claim 1; and an image forming unit configured to form an image on a sheet material conveyed by the conveying device. Forming equipment.