JP2000259041A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a meandering regulating member provided on a toner image carrier stably engaged with a engaging part formed on a toner image carrier roller. SOLUTION: This image forming device is provided with the toner image carrier 1, equipped with the meandering control member 1c composed so that a leading end part is outwardly deviated with respect to the rotary direction is disposed in the peripheral direction at one hand side on the rear side, and moreover, the peripheral length on the side provided with the meandering control member 1c is longer than the peripheral length on the side the meandering regulating member 1c is not provided, and provided with plural toner image carrier supporting rollers 2 stretching/supporting the toner image carrier 1, provided with the engaging part 2a that the meandering control member 1c is ruggedly engaged therewith when the toner image carrier 1 is peripherally rotated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using a toner image carrier and an intermediate transfer belt.

[0002]

2. Description of the Related Art In recent years, toner-type image forming apparatuses capable of forming clear images with excellent resolution, such as laser printers, have become widespread. Among such toner-type image forming apparatuses, an image forming apparatus using a photosensitive belt as a toner image carrier is very suitable for promoting colorization due to its configuration.

Hereinafter, a conventional image forming apparatus using such a photosensitive belt will be described.

FIG. 3 is a view showing an example of a toner image carrier in a conventional image forming apparatus, FIG. 4 is a view showing another example of a toner image carrier in a conventional image forming apparatus, and FIG. FIG. 4 is an explanatory diagram illustrating an example of a toner image carrier provided with a position regulating unit in the image forming apparatus.

An endless belt-shaped toner image carrier (endless belt-shaped image carrier) 1 whose surface is coated with a layer of an organic photoconductive material has a plurality of toner image carrier support rollers (support rollers) 2. It is supported and is rotated around. Around black toner (K), yellow (Y), magenta (M), and cyan (C), a developing unit, a cleaning unit, a discharging unit, a charging unit, and an exposing unit are provided around the toner image carrier 1. Have been. Further, an intermediate transfer belt (endless belt-shaped image carrier) is provided in contact with the toner image carrier 1. An intermediate transfer roller for transferring the toner image on the toner image carrier 1 onto the intermediate transfer belt is provided.

In such an image forming apparatus, the surface of the toner image carrier 1 is uniformly charged, for example, black (K)
When the laser light corresponding to the image (1) is irradiated, an electrostatic latent image is formed on the toner image carrier 1. When the toner from the developing unit containing the black toner transfers to the electrostatic latent image, a visible toner image appears on the toner image carrier 1. The toner image on the toner image carrier 1 is transferred onto an intermediate transfer belt by an intermediate transfer roller.

In the case of four-color development, such a developing operation is sequentially repeated four times, and a composite image is formed by superimposing toner images of four colors K, C, M, and Y on the intermediate transfer belt. .

In the conventional image forming apparatus as described above, in order to prevent the toner image carrier 1 from shifting in the thrust direction during the rotation operation, as shown in FIG. 3, a meandering restricting member 1c is provided at one end of the back surface. It is provided over the entire circumference, and welding is performed so that the circumference 1a on the side where the meandering regulating member 1c is provided is longer than the circumferential length 1b on the other side. 1c is provided with a fitting portion 2a in which concave and convex are continuously fitted, or as shown in FIG. 4, the toner image carrier supporting roller 2 supporting the toner image carrier 1 is subjected to taper (outer diameter difference) processing. The toner image carrier 1 is moved in one direction of the rotation axis of the toner image carrier support roller 2 to fit the meandering regulating member 1c and the fitting portion 2a.

[0009]

However, in such a conventional toner image carrier 1, since there is no restriction on the position of the end face mating portion in the circumferential direction of the meandering restricting member 1c, as shown in FIG. There is a case where the fitting portion is displaced.

Then, when the toner image carrier 1 rotates, the meandering restricting member 1c is disengaged from the fitting portion 2a, instantaneous misalignment occurs to damage the toner image carrier 1, and print misalignment occurs. Wake up.

Such a problem also occurs in the intermediate transfer belt on which the toner image on the toner image carrier 1 is transferred.

Accordingly, the present invention provides an image forming apparatus capable of stably fitting a meandering regulating member provided on an endless belt-shaped image carrier to a fitting portion formed on a support roller. Aim.

[0013]

In order to solve this problem, in the image forming apparatus of the present invention, a meandering regulating member formed such that a front end in a rotation direction is shifted outward from a rear end is provided on a back surface. While being provided in the circumferential direction on one end side,
An endless belt-shaped image carrier in which a circumferential length on the side where the meandering regulating member is provided is longer than a peripheral length on the side where the meandering regulating member is not provided; and an endless belt-shaped image carrier. The meandering regulating member is provided with a fitting portion in which the meandering restricting member is fitted into the concave and convex portions when the belt rotates circumferentially, and has a plurality of support rollers for adjusting and supporting the endless belt-shaped image carrier.

According to this, the meandering regulating member provided on the endless belt-shaped image carrier can be stably fitted to the fitting portion formed on the support roller.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, the meandering regulating member formed with the front end in the rotation direction being shifted outward from the rear end is formed in the circumferential direction at one end of the back surface. And an endless belt-shaped image carrier in which the circumferential length on the side where the meandering regulating member is provided is given a longer circumferential length difference than the circumferential length on the side where the meandering limiting member is not provided. An image forming apparatus comprising: a plurality of support rollers for adjusting a belt-shaped image carrier when a belt-shaped image carrier is provided with a fitting portion in which a meandering regulating member fits in a concave-convex shape when the belt-shaped image carrier is rotated. This has the effect that the meandering regulating member provided on the endless belt-shaped image carrier can be stably fitted to the fitting portion formed on the support roller.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In these drawings, the same members are denoted by the same reference numerals, and duplicate description is omitted.

FIG. 1 is a schematic diagram showing an image forming apparatus according to an embodiment of the present invention, and FIG. 2 is an explanatory view showing a toner image carrier together with a toner image carrier supporting roller in the image forming apparatus of FIG. .

In FIG. 1, a toner image carrier (endless belt-shaped image carrier) 1 having an endless belt shape and the surface of which is coated with a layer of an organic photoconductive material has three toner image carrier support rollers (supports). The roller is supported by an adjusting band so as to form a horizontal surface on one side by a roller 2 and is rotated around in the direction of arrow A by a drive motor (not shown). The toner 4Kb, 4Yb, 4 having a negative charge polarity of each color of black (K), yellow (Y), magenta (M), and cyan (C) is formed on the upper portion of the toner image carrier 1 along the outer peripheral surface thereof.
Mb, 4Cb are stored and the developing rollers 4Ka,
Developing means 4 with 4Ya, 4Ma, 4Ca attached
K, 4Y, 4M, and 4C are provided. The present invention does not need to be such a four-color development, but may be a two-color or three-color development.

Around the toner image carrier 1, there are a cleaning means 6, a charge removing means 5, and a charging means 3. On the side of the toner image carrier 1, an exposure means 7 for irradiating a laser beam is provided. I have. The portion of the toner image carrier 1 that has passed through the charging means 3 by corona discharge by the charging means 3
Are uniformly charged, the charge of the toner image carrier 1 is partially lost by the laser beam of the image data emitted from the exposure unit 7, and the toner image carrier 1 has a plurality of predetermined color components. A plurality of electrostatic latent images corresponding to specific components are formed.

The exposure means 7 includes an LED or an LC.
D or the like can also be used. Further, developing means 4 for each color
K, 4Y, 4M, and 4C are arranged in a predetermined storage section provided in the apparatus main body at equal intervals and removably in a horizontal row (horizontal direction). , 4Yb, 4Mb, and 4Cb except for the types.

When developing an electrostatic latent image of a predetermined color corresponding to each of the developing means 4K, 4Y, 4M, and 4C, the respective developing means 4K, 4Y, 4M, and 4C are transferred to the toner image carrier 1.
Contact cams 8K, 8Y, 8M, and 8C are provided for contact with the developing means 4K, 8K, 8Y, 8M, and 8C.
Separation springs 10K, 10Y, 10M, and 10C are provided to separate the 4Y, 4M, and 4C to the standby position when they are not pushed down toward the toner image carrier 1.

The intermediate transfer unit 11 includes a belt-like intermediate transfer belt (endless belt-shaped image carrier) 9 made of a conductive resin or the like, and three intermediate transfer belt supports on which the intermediate transfer belt 9 is adjusted. Rollers (supporting rollers) 12a, 12
b, 12c. In order to transfer the toner image 4 </ b> C on the toner image carrier 1 onto the intermediate transfer belt 9, an intermediate transfer roller 13 is arranged to face the toner image carrier 1 with the intermediate transfer belt 9 interposed. Here, the surface circumference of the intermediate transfer belt 9 is set to be equal to the surface circumference of the toner image carrier 1.

An intermediate transfer belt cleaning device 14 is provided near the intermediate transfer belt support roller 12b in order to scrape off residual toner on the intermediate transfer belt 9. The intermediate transfer belt cleaning device 14 is separated from the intermediate transfer belt 9 while a synthetic image is formed on the intermediate transfer belt 9, and comes into contact with the intermediate transfer belt 9 only when it is used for cleaning.

A paper cassette 16 for storing paper 15 is provided directly below the toner image carrier 1. And
The paper 15 is sent out one by one from a paper cassette 16 to a paper transport path 18 by a paper feed roller 17. In order to match the position of the sheet 15 with the composite image formed on the intermediate transfer belt 9, a registration roller 19 for temporarily stopping and waiting the sheet 15 is provided in pressure contact with the driven roller 20. Further, a paper transfer roller 21 for transferring the composite image formed on the intermediate transfer belt 9 to the paper 15 is provided on the paper transport path 18.
Only when the image is transferred to the intermediate transfer belt 5, the intermediate transfer belt 9 is rotated.

In order to fix the composite image transferred to the sheet 15, a fixing device 24 including a heat roller 22 having a heat source therein and a pressure roller 23 is disposed. Then, as the paper 15 passes through the fixing device 24, the composite image transferred by the pressure and heat is fixed by the pinch rotation of the heat roller 22 and the pressure roller 23, and a color image is formed.

On the downstream side of the fixing device 24, a pair of discharge rollers 2 is provided.
5, 26 are provided. At the rear end of the paper transport path 18, a paper discharge tray 27 provided at the upper part of the machine is installed, where the paper 15 is accumulated.

Here, as shown in FIG. 2, on one end side of the back surface of the toner image carrier 1, a convex meandering regulating member 1c is provided along the circumferential direction. Further, the toner image carrier support roller 2 on which the toner image carrier 1 is supported is provided with a concave fitting portion 2a into which the meandering restricting member 1c fits when the toner image carrier 1 rotates around. I have. The meandering regulating member 1c is formed such that the leading end in the rotation direction of the toner image carrier 1 is shifted outward from the trailing end.

Further, in the toner image carrier 1, there is a difference in circumferential length such that the circumferential length on the side where the meandering regulating member 1c is provided is longer than the circumferential length on the side where the meandering limiting member 1c is not provided. Has been given.

Such a configuration can be similarly applied to the intermediate transfer belt 9. That is,
Such a configuration can be adopted for at least one of the endless belt-shaped image carrier of the toner image carrier 1 and the intermediate transfer belt 9.

In this embodiment, the meandering restricting member 1c is formed in a convex shape and the fitting portion 2a is formed in a concave shape. However, the meandering restricting member 1c is formed in a concave shape, and the fitting portion 2a is formed in a convex shape. It may be. In other words, it is only necessary that the meandering restricting member 1c and the fitting portion 2a fit into the concave and convex portions.

The operation of the image forming apparatus configured as described above will be described below.

In FIG. 1, first, the surface of the toner image carrier 1 is uniformly charged by corona discharge in the charging means 3 connected to a high voltage power supply.

Next, the toner image carrier 1 is rotated in the direction of arrow A by a driving device (not shown), and the surface of the uniformly charged toner image carrier 1 has a predetermined color component among a plurality of color components. When a laser beam corresponding to a black (K) image, for example, is irradiated, the irradiated portion on the toner image carrier 1 loses the charge, and is exposed in a pattern corresponding to the image signal to form an electrostatic latent image. It is formed.

On the other hand, black toner 4 contributing to development
The developing means 4K in which Kb is stored is brought into contact with the toner image carrier 1 when the contact cam 8K makes a half turn according to a color selection signal from a host computer (not shown).

Developing rollers 4Ka, 4Ya, 4Ma, 4C
a, a bias voltage is applied to the developing roller 4K.
a, 4Ya, 4Ma, 4Ca Surface and Toner Image Carrier 1
The toner 4Kb is transferred only to the portion of the toner image carrier 1 irradiated with the laser beam due to the electric field acting between the toner image carrier 1 and the toner image 4C as a visible image appears on the toner image carrier 1.

The developing means 4K, which has completed the development, moves from the contact position with the toner image carrier 1 to the standby position by the spring force of the separation spring 10K when the contact cam 8K further rotates by half. While the developing unit 4K is developing, the other developing units 4Y, 4M, and 4C are separated from the toner image carrier 1.

The toner image 4C formed on the toner image carrier 1 by the developing means 4K is transferred onto the intermediate transfer belt 9 by a bias voltage applied to the intermediate transfer roller 13.

Next, when the color of cyan (C) is selected, for example, the developing means 4C is brought into contact with the toner image carrier 1, and the development of cyan is started by the same operation as described above. In the case of a copying machine or a printer using four colors, such a developing operation is sequentially repeated four times, and the toner images 4C of four colors K, C, M, and Y are superimposed on the intermediate transfer belt 9 to form a composite image. To form

The composite image formed in this manner is applied to the paper transfer roller 21 by the toner 4Kb, 4Yb, 4Mb, 4Cb.
When a high voltage of the opposite polarity is applied, the sheet is transferred onto the sheet 15 sent from the sheet cassette 16 along the sheet conveying path 18 by the pressure, and then sent to the fixing device 24.
Then, the image is fixed by the heat and the clamping force between the heat roller 22 and the pressure roller 23 to form a color image. Fixing device 2
The sheet 15 that has passed through the sheet 4 passes through a pair of sheet discharge rollers 25 and 26 and is discharged to a sheet discharge tray 27.

Here, as described above, the toner image carrier 1
A convex meandering regulating member 1c is provided at one end of
The toner image carrier support roller 2 is provided with a fitting portion 2a. Further, the meandering restricting member 1c is provided with the toner image carrier 1
Is formed such that the front end thereof in the rotation direction is shifted outward from the rear end. Further, the peripheral length of the toner image carrier 1 on the side where the meandering restricting member 1c is provided is
The circumferential length difference is given so as to be longer than the circumferential length on the side where c is not provided. The intermediate transfer belt 9 has the same configuration.

In such a toner image carrier 1, the meandering regulating member 1c and the fitting portion 2a are fitted to each other,
The rotation in a state where the movement to the side where the meandering regulating member 1c is not provided is prevented. When the rear end of the meandering restricting member 1c in the rotation direction passes through the fitting portion 2a, the toner image carrier 1 moves to the side where the meandering restricting member 1c is not provided, and is moved outward from the rear end. The shifted tip is fitted into the fitting portion 2a.

Thus, the meandering restricting member 1c provided on the toner image carrier 1 can be stably fitted to the fitting portion 2a formed on the toner image carrier support roller 2.

The same operation is performed on the intermediate transfer belt 9.

In this embodiment, a color image forming apparatus using an intermediate transfer system is described. However, the present invention is applied to various image forming apparatuses employing an endless belt-shaped toner image carrier 1. be able to.

[0045]

As described above, according to the present invention, the meandering regulating member provided on the endless belt-shaped image carrier can be stably fitted to the fitting portion formed on the support roller. Is obtained.

As a result, when the endless belt-shaped image carrier rotates, the meandering restricting member comes off the fitting portion, instantaneous misalignment occurs to damage the endless belt-shaped image carrier, or print misalignment occurs. And an effective effect that high-quality image formation can be performed can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an image forming apparatus according to an embodiment of the present invention;

FIG. 2 is an explanatory diagram showing a toner image carrier in the image forming apparatus of FIG. 1 together with a toner image carrier support roller;

FIG. 3 illustrates an example of a toner image carrier in a conventional image forming apparatus.

FIG. 4 is a diagram illustrating another example of a toner image carrier in a conventional image forming apparatus.

FIG. 5 is an explanatory diagram illustrating an example of a toner image carrier provided with a position regulating unit in a conventional image forming apparatus.

[Explanation of symbols]

Reference Signs List 1 toner image carrier (endless belt-shaped image carrier) 1c meandering regulating member 2 toner image carrier support roller (support roller) 2a fitting portion 9 intermediate transfer belt (endless belt-shaped image carrier) 12a, 12b, 12c intermediate Transfer belt support roller (support roller)

Claims (1)

[Claims] 1. A meandering restricting member formed so that a front end thereof is deviated outwardly from a rear end with respect to a rotational direction, and is provided in a circumferential direction on one end side of a back surface, and a side on which the meandering restricting member is provided. The endless belt-shaped image carrier provided with a peripheral length difference longer than the peripheral length on the side where the meandering regulating member is not provided, and when the endless belt-shaped image carrier rotates circumferentially. An image forming apparatus, comprising: a plurality of support rollers provided with a fitting portion in which the meandering restricting member is fitted into concave and convex portions, and supporting the endless belt-shaped image carrier in a band.