JPH03249671A - color electrophotographic equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention develops electrostatic latent images corresponding to each color separated and formed on a photoreceptor with toner of each color, and once the toner images of each color are formed into a belt. The present invention relates to a color electrophotographic device that performs overlapping transfer on a transfer body and then transfer to paper.

Conventional technology An electrophotographic technique in which an electrostatic latent image corresponding to the original image is formed on a photoreceptor, then developed using monochrome toner, transferred and fixed onto paper, and the photoreceptor surface is cleaned and the same operation is repeated again. The device is known (R,M.

by 5chaffertrE1electrophotogr
aphyJ The Focal Press 1965
(see annual publication). Color electrophotographic apparatuses that repeat similar operations using multicolor toners are also known.

In a conventional color electrophotographic apparatus, electrostatic latent images corresponding to each separated color are first formed on a photoreceptor. Next, development is performed using toners of each color, and the resulting toner images of each color are superimposed on a sheet of paper on a conveying member, transferred, and fixed to obtain a color copy image.

A single photoreceptor may be used, or a plurality of photoreceptors having different spectral sensitivities may be used. Further, the photoreceptor may be drum-shaped or belt-shaped.

As a method that does not require a complicated mechanism for attaching and detaching paper to and from the conveyor, the toner image formed on the photoconductor is first superimposed and transferred onto a drum-shaped or belt-shaped intermediate transfer member, and then transferred to the paper. A method has also been proposed to
(Refer to Publication No.-90972).

In such conventional color electrophotographic devices, high-quality color copy images should be obtained if each part inside the device operates ideally and according to theory, but the photoreceptor, intermediate transfer member,
If the driving means such as the paper conveyance mechanism is not modified in some way, synchronization may occur, and when the toner images are transferred onto the paper in an overlapping manner, the toner images of each color will be misaligned. Therefore, the image quality of the resulting color copies is significantly reduced.

For this reason, when using a system that uses multiple photoreceptor belts, the circumferential length of the drive roller of the photoreceptor belt is set to 1/an integer of the distance from each image exposure position to the transfer position to prevent misalignment of overlapping transferred images. It has also been proposed that (
(See Japanese Patent Application Laid-Open No. 129873/1983).

Problems to be Solved by the Invention However, in the conventionally proposed methods for preventing misalignment of transferred images, eccentricity of gears, rollers, etc. used in the drive mechanism of drums and belts, and bearings are It is possible to remove positional deviations caused by periodic fluctuations due to deformation of the belt, etc., but image positional deviations caused by large synchronization differences between the photoconductor and transfer body, unilateral changes in belt length, etc. must be removed. I can't. It is also difficult to completely control the circumferential length l of the photoreceptor belt and the intermediate transfer belt.

Initially, even if the position of the photoreceptor belt is adjusted so that the seam does not overlap the image area of the intermediate transfer belt, as the number of rotations increases, the position of the seam will gradually shift relative to the photoreceptor belt, causing the image area to overlap. The belt seams will overlap. As a result, there is also the problem that the composite color images on the intermediate transport belt are also disturbed. To prevent this, it is necessary to adjust the position of the seam after a certain number of laps have passed, but if the ratio of the circumferential lengths of the two belts is larger or smaller than Since the moving directions of the overlapping positions are different, there is also the problem that adjusting the positions requires a very complicated control method.

The present invention solves the above problems, and even if the relative position between the photoreceptor belt and the transfer belt changes or the belt length changes, the transferred image of each color toner image will not be misaligned. The object of the present invention is to provide a color electrophotographic device that does not cause color electrophotography.

Means for Solving the Problems In order to solve the above problems, the present invention provides a color electrophotographic apparatus equipped with one photoreceptor belt and one intermediate transfer belt. The circumferential length range is set so that the circumferential length of the belt is always shorter than n times the circumferential length of the intermediate transfer belt (n is a positive integer), and the driving of the light source belt and the intermediate transfer belt is is carried out from a common drive source, and is equipped with a clutch mechanism that temporarily interrupts power transmission to the drive system of the photoreceptor belt.As a second combination that is the opposite of this, the circumference of the photoreceptor belt l The range of the circumferential length l is set so that the value is always n times the circumferential length l of the intermediate transfer belt (m is a positive integer), and the drive of the photoreceptor belt and the intermediate transfer belt is shared. The intermediate transfer belt is driven by a drive source, and is equipped with a clutch mechanism that temporarily interrupts power transmission to the drive system of the intermediate transfer belt.

Function The present invention has the above-described structure, and the two of the photoreceptor and the intermediate transfer member are
Since the relationship between the length and shortness of the circumference of the book belt is fixed, the direction in which the position where the seam of the photoreceptor belt touches the intermediate transfer belt moves each time it goes around is specified, and this allows It becomes possible to temporarily cut off the power transmission of the drive system and adjust the position where the joints meet.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 3.

As shown in Figure 1, a photoreceptor belt (photoreceptor) 1 has a photoreceptor layer made of selenium or an organic photoconductor provided on the outer peripheral surface of a closed-loop plastic film. A closed-loop intermediate transfer belt (
It is arranged between a drive roller 3 and a freely rotating roller 4 while being in contact with an intermediate transfer member (intermediate transfer member) 2. The intermediate transfer body 2 is still arranged between the drive roller 5 and the freely rotating roller 6. A charger 7, an optical device 8, developing devices 9a, 9b, 9c, 9d, a cleaner 1o, a sensor 11, and the like are provided around the photoreceptor 1. A transfer device 12 is installed around the intermediate transfer body 2.
, a cleaner 13 and a sensor 14 are provided. Further, a transfer device 15 is provided so as to be able to come into contact with and separate from the intermediate transfer body 2, and the paper 17 fed from the paper cassette 16 passes through the edge where the toner image on the intermediate transfer body 2 was transferred and a fixing device 18. It has a structure like this. A drive motor (drive source) 19 drives the intermediate transfer belt 2 and transmits its power to the drive roller 3 of the photoreceptor belt 1 through the power transmission mechanism 2o. A clutch mechanism 21 controls the rotational speed of the drive roller 3 of the photoreceptor 1 by connecting/disconnecting power from the drive motor 19 .

To explain the operation of the above configuration, the photoreceptor 1 is irradiated with separated light images of each color, and corresponding toner images of each color are formed. These toner images of each color are superimposed and transferred onto the intermediate transfer member 2, and then transferred onto the paper 17.
The image is fixed and a color copy image is obtained.

The above operations are performed by known methods.

Next, the driving method and operation of the photoreceptor 1 and the intermediate transfer member 2 will be explained. In FIG. 2, the intermediate transfer belt 2
It is assumed that the portion of the person in the above figure is a non-image weather measurement area in which no image is formed, and that the photoreceptor belt 1 is rotated within this area so that the seam 1a of the photoreceptor belt 1 is in contact with it. When the recording operation is repeated in this state and the number of rotations of the two belts, photoreceptor belt 1 and intermediate transfer belt 2, is increased, the circumference l of both belts increases, and the intermediate transfer belt 2 moves. Here, the circumferential length 21 of the photoreceptor belt 1 and the circumferential length 22 of the intermediate transfer belt 2 are almost equal, but if they are set so that the relationship xl<p, 2 holds, the seam position The direction of movement of is specified. FIG. 3 is a diagram showing the state after a predetermined number of circuits have passed. In this state, the seam 1a of the photoreceptor belt 1 has reached very close to the end of the non-image area of the intermediate transfer belt 2, and therefore needs to be adjusted again. Therefore, the clutch mechanism 21 installed on the drive shaft of the photoreceptor belt 1 cuts off the power for a predetermined period of time to stop or decelerate the rotation of the photoreceptor belt 1, thereby reproducing the state shown in FIG. The clutch mechanism 21 is connected to the clutch mechanism 21 to restart rotation.

As described above, according to this embodiment, the circumferential length l21 of the photoreceptor belt 10 and the circumferential length lβ2 of the intermediate transfer belt 20 are made approximately equal, and the dimensional error during belt manufacturing is reduced.

By setting the circumferential length l of both belts so that the difference in circumferential length l between both belts based on the change in circumferential length l during use always satisfies 21<β2, it is possible to prevent non-images on the intermediate transfer belt 2. It is possible to specify the contact position and moving direction of the seam 1a of the photoreceptor belt 1, and also to drive the intermediate transfer belt 2 and the photoreceptor belt 1 using a common drive source (drive motor 9).
), and by providing the drive system of the photoreceptor belt 1 with a clutch mechanism 21 that temporarily interrupts power transmission,
The contact position between the non-image area of the intermediate transfer belt 2 and the seam 1a of the photoreceptor belt 1 can be adjusted in a simple manner.

Alternatively, the relationship between the circumferential length l21 of the photoreceptor belt 1 and the circumferential length l2 of the intermediate transfer belt 2 may be reversed to 21>I12, and a clutch mechanism may be provided on the drive roller 5 of the intermediate transfer belt 2 to obtain the same effect. can be obtained. Furthermore, ft, 1〈nR2 (n is a positive integer) or 21〉nβ2
(n is a positive integer), the same effect can be obtained. Further, in this embodiment, position adjustment is performed using a clutch mechanism, but the same effect can be obtained by using a brake mechanism or the like.

Although this embodiment describes the case where both the photoreceptor and the intermediate transfer body are belt-shaped, it is clear that the same effect can be obtained even if one or both of them are drum-shaped. .

Effects of the Invention In the present invention, as a first combination, the circumference l of the photoreceptor belt is n times the circumference l of the intermediate transfer belt (n is a positive integer).
The circumference l of the belt is set to be approximately equal to and always shorter than the circumference l, and the photoreceptor belt and the intermediate transfer belt are driven by a common drive source to drive the photoreceptor belt. The system is equipped with a clutch or brake mechanism that temporarily interrupts power transmission. A second combination that is opposite to this is to make the circumferential length l of the photoreceptor belt approximately equal to n times the circumferential length l of the intermediate transfer belt (n is a positive integer), and A clutch that sets the circumference l so that it is always a long value, drives the photoreceptor belt and the intermediate transfer belt from a common drive source, and temporarily interrupts power transmission to the drive system of the intermediate transfer belt. It is equipped with a mechanism or a brake mechanism,
As a result, the relationship between the circumferential length l of the two belts is fixed, so the direction in which the position where the seam of the photoreceptor belt contacts the intermediate transfer belt moves for each circumference is specified. As a result, adjustments can be made simply by temporarily interrupting the power transmission of the shorter-cycle drive system, thereby providing an excellent color electrophotographic device in which the control mechanism for adjustment is greatly simplified. be able to.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a color electrophotographic apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating the contact position of a photoreceptor belt on an intermediate transfer belt according to an embodiment of the present invention after adjustment. FIG. 3 is a schematic diagram of the main part before adjustment. DESCRIPTION OF SYMBOLS 1... Photoreceptor belt, 2... Intermediate transfer belt, 8... Optical device, g a, 9
b, 9c, 9d...Developing device, 1
9... Drive motor (drive source), 2o...
- Power transmission mechanism, 21...Clutch mechanism.

Claims (3)

[Claims] (1) Color electrophotography in which color-separated optical images are formed on a photoreceptor belt, developed with corresponding color toners, and the resulting color toner images are sequentially superimposed and transferred onto an intermediate transfer belt. In the device, the circumference of the photoreceptor belt l_
1 is an integral multiple of the circumferential length l_2 of the intermediate transfer belt n・l_2
(where n is a positive integer) while in use near l_1<n・
The circumferential lengths of the photoreceptor belt and the intermediate transfer belt are set so that the relationship l_2 or l_1>n・l_2 is always maintained, and the photoreceptor belt and the intermediate transfer belt are driven by the same drive source. However, if l_1<n・l_2, a clutch mechanism or a brake mechanism is provided in the drive system of the photoreceptor belt, and if l_1>n・l_2, a clutch mechanism or a brake mechanism is provided in the drive system of the intermediate transfer belt. color electrophotographic equipment. (2) The color electrophotographic apparatus according to claim (1), further comprising a photoreceptor drum in place of the photoreceptor belt. (3) The color electrophotographic apparatus according to claim 1 or 2, further comprising an intermediate transfer drum instead of the intermediate transfer belt.