JP2001265081A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of suppressing the extension or the contraction of the image accompanying the transfer based on slip transfer system and also suppressing each color blurring of the toner image caused by transferring process repeated twice or more. SOLUTION: When assuming the speed difference between the image carrying rotary body and the transfer rotary body as ΔV1, and the speed difference between the above rotary body and the recording medium or another transfer rotary body as ΔV2, subject the above image carrying rotary body speed and the above transfer rotary body speed or the recording medium speed are set so that codes, the that is, + or - of speed difference ΑV1 and the speed difference ΑV2 differs each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color copying machine, a color printer, and the like which employ an image forming system such as an electrophotographic system, an electrostatic recording system, an ionography, and a magnetic recording system.
For image forming apparatuses such as color and facsimile,
The toner images of different colors formed on one or a plurality of image bearing rotators are transferred in a state of being superimposed on a single or a plurality of transfer rotators, and if necessary, another transfer rotator is further transferred. Motion control (driving) applied to an image forming apparatus having at least two or more transfer steps of forming a full-color image by superimposing all the toner images on the above and finally transferring them collectively on a recording medium Control) technology.

[0002]

2. Description of the Related Art In an image forming apparatus such as a color copying machine or a color printer which employs a well-known electrophotographic system or the like, a toner image is transferred from a photoconductor to a sheet, or a photoconductor to an intermediate transfer roll or an intermediate transfer belt. Although there are some differences in the configuration from an intermediate transfer member to a sheet or from the first intermediate transfer member to a sheet through a second intermediate transfer member, they are roughly classified into two processes. One is a tack transfer process in which paper is transferred while being electrostatically attracted to a photoreceptor or the like, and the other is a slip transfer process in which paper is transferred while generating a speed difference between components. .

[0003] The difference between these two process mechanisms is described in Japan Hardcopy '9 published by the present inventors.
9 A detailed explanation is given in “Research on Slip Transfer Mechanism” (p42-p45) of the 84th Annual Meeting of the Imaging Society of Japan at the Fall Meeting. In a so-called tandem type image forming apparatus that is arranged in series, factors that affect the color registration of the photoconductor include geometric eccentricity, a difference in the photoconductor diameter, and a difference in the average angular velocity in the photoconductor shaft portion. And so on. In multiple transfer type color printers and color copiers where the toner image is transferred multiple times while the photoconductor and transfer drum rotate synchronously multiple times, the eccentricity of the photoconductor and transfer drum and the angular velocity at the shaft Technology to secure "synchronous" such as making the reduction ratio of the meshing gear of the drive transmission system an integer multiple, and increasing the circumference of the drive roll for driving the intermediate transfer belt and the photoconductor pitch to the integer multiple. By adopting the concept, it is possible to ensure the reproducibility of the so-called motion quality of the components related to the image formation that rotates or moves. By realizing the reproducibility of the motion quality, it is possible to minimize the deviation between colors.

However, a disadvantage of the multiple transfer type image forming apparatus is that the photosensitive member, the transfer drum, or the intermediate transfer belt is rotated a plurality of times in synchronization with each other.
The formation of a color image does not increase print productivity.

On the other hand, in a tandem type image forming apparatus, well-known electrophotographic components including a photoreceptor for forming a toner image are provided for each color, and sheets are basically transported one after another while being transported straight. A color print can be produced at high speed by sequentially superimposing and transferring the visualized toner images of the respective colors on paper or an intermediate transfer member.

However, as described above, in the tandem type image forming apparatus, since the image forming units for each color function independently, the color eccentricity of a plurality of photoconductors and the difference of the average angular velocity in the shaft portion are different. A large number of factors greatly influence the shift, and therefore, the technical issues for minimizing the color shift and realizing highly accurate motion quality become extremely high.

The mechanism of the slip transfer is such that geometrical errors of the photoconductor and the like which are particularly problematic in such a tandem type image forming apparatus, error factors such as a difference in the photoconductor diameter and a difference in the average angular velocity in the shaft portion. It is characterized in that it has a canceling effect that does not affect the color shift that occurs on the paper.

Also, the so-called hollow character phenomenon in which the central portion of the fine line comes off can be improved by providing a certain speed difference between these components, and the transfer efficiency can be improved at the same time. Kaihei 10-39648,
It is described in JP-A-62-35137 and the like. For example, when a toner image formed on a photoreceptor is transferred to an intermediate transfer belt, forces acting between these components include electrostatic attraction to charged toner due to a transfer electric field, and a transfer force between the toner and the photoreceptor. There are five main types of forces: adhesion, toner cohesion, adhesion between toner and the intermediate transfer belt, and gravity acting on toner. In the transfer nip portion, the electrostatic attraction force acts dynamically, so this force also changes, but the toner image height at the center is high as in a line image with a width of about 60 to 200 μm. With a convex shape, this force particularly increases the cohesive force between toners in the central portion. The cohesive force between the toners in the central portion of the line image is a cause of hollow hollow and causes a hollowing-out phenomenon. By setting the appropriate speed difference, the effect of suppressing the cohesion of the toners is reduced. It is believed to have brought.

[0009] By setting an appropriate speed difference between the components for transferring the toner image, it is possible to obtain a merit in motion quality by making good use of the slip transfer mechanism (particularly in a tandem type image forming apparatus). An advantage is that defects relating to images, such as improvement of hollow characters and transfer efficiency, can be reduced.

[0010]

However, such a slip transfer process has a speed dependency on the image receiving side on which the toner image is transferred. For example, when a toner image formed on a photoconductor is transferred onto an intermediate transfer belt, a color resulting from a geometric error such as eccentricity of the photoconductor, a diameter difference between a plurality of photoconductors, and a difference in average angular velocity in an axis. Even if the influence of the deviation can be canceled, the average speed of the intermediate transfer belt itself has a bias with respect to the average speed of the photoconductor, so that the image naturally expands and contracts.

In the case of a photosensitive member and an intermediate transfer belt in a conventional multiple transfer type image forming apparatus, the transfer
The number of transfer steps related to shrinkage can be considered as one. Therefore, the speed difference of about 0.5% (absolute value: the case where the photoconductor is faster than the intermediate transfer belt and the case where the photoconductor is slower as described in ), The degree of influence on the expansion / contraction of the image does not increase. For example, assume that one dot is recorded by a laser optical system having an output resolution of 600 dpi with an average speed of 100 mm / s and a speed difference of 0.5%. The diameter of one dot on the photoreceptor varies greatly depending on the latent image forming conditions, but it is assumed that a latent image is formed on the photoreceptor with an average size of about φ40 μm. In this case, the expansion / contraction ΔX of the image is expressed by the following equation (1).
Given by the formula.

[0012]

(Equation 1)

[0013] In this case, ΔX: expansion or contraction (m) V _pap> V _PR image is extending direction of the transfer image (+) V _pap <V _PR image shrinks direction (-) V _pap: Paper speed (m / s ) V _PR : Photoconductor speed (m / s) W: Nip width (m) V ₀ : Average speed

The nip width also varies greatly depending on the configuration and process of the image forming apparatus. However, assuming that the image expands and contracts while slipping for a physical width of about 5 mm, ΔX is given by the following equation (2). Can be estimated as in the formula.

[0015]

(Equation 2)

It can be seen that when the toner image is formed faithfully on the electrostatic latent image, the diameter of one dot on the final paper is about φ65 μm. The above assumption is based on the case where the slip transfer between the photosensitive member and the paper is ideally performed, and this value fluctuates due to other error factors. Of course,
If the speed difference is constant, the input image signal in the paper transport direction (or the photoconductor rotation direction) may be expanded or reduced in advance in consideration of the expansion and contraction in the process. However, there is a tendency that image control becomes complicated and unstable.

As described above, in the process in which the slip transfer transfer functions, image expansion and contraction occur, and there are at least two or more transfer steps related to the image expansion and contraction as in the image forming apparatus according to the present application. It is expected that the amount of change will be quite large for the case.
In addition, in two or more transfer steps, there is a problem that the toner image of each color is shifted due to expansion and contraction of the image.

Therefore, the object of the present invention according to the present application has been made in view of such conventional problems, and it is possible to suppress expansion and contraction of an image due to transfer by a slip transfer method. An object of the present invention is to provide an image forming apparatus capable of suppressing a deviation of a toner image of each color due to two or more transfer steps.

[0019]

According to a first aspect of the present invention, a latent image is formed in accordance with input information for each color, and each latent image is formed with a toner of a corresponding color. An image forming apparatus that forms a color image by developing to obtain a plurality of single-color toner images and fixing the plurality of single-color toner images on a recording medium, wherein each latent image corresponding to input information for each color is provided. Are formed, and each latent image is developed with a toner of a corresponding color to form a single-color toner image. Three or more image-bearing rotating members arranged so as to have a common tangent plane, or A single image-bearing rotating body in which each latent image corresponding to the input information is sequentially formed, and each latent image is developed with a toner of a corresponding color to sequentially form each single-color toner image; A single image-bearing rotating body is placed in contact with or in close proximity to the rotating body, And one or a plurality of transferring member each single color toner image formed on the lifting rotary member is transferred,
An image forming apparatus comprising: a transfer electric field applying rotator for transferring the toner image transferred onto the one or more transfer rotators to a recording medium; When the speed difference is ΔV ₁ and the speed difference between the transfer rotator and the recording medium or another transfer rotator is ΔV ₂ , the speed of the image bearing rotator is different from the speed difference ΔV ₁ so that the sign of the speed difference ΔV ₂ is different. An image forming apparatus wherein the speed of the transfer rotator or the speed of the recording medium is set.

Here, as a further desirable configuration for achieving the object of the invention according to the present application, each latent image corresponding to the input information for each color is formed, and each latent image is developed with a toner of a corresponding color. Three or more image-bearing rotators arranged so as to have a common tangent plane on which each single-color toner image is formed, and contact for transferring the single-color toner image formed on the image-bearing rotator Or a first surface having a flexible surface or an elastic surface disposed close to each other, and each rotation axis being parallel to the image-bearing rotation body axis and having a surface object relation with a predetermined object surface as a boundary. A transfer rotator and a second transfer rotator, and a flexible surface or an elastic surface disposed in contact or close proximity to transfer the toner images on the first and second transfer rotators. And the rotating shaft is parallel to the image bearing rotating body. 3 and transferring member of an image forming apparatus comprising a transfer electric field applying roller for transferring the recording medium the toner image transferred on the transferring member on the third.

However, the invention according to the present application is not limited to the above configuration, and each latent image according to the input information for each color is sequentially formed, and each latent image is developed with the toner of the corresponding color. A single image-bearing rotator on which each single-color toner image is sequentially formed may be provided, and the image-bearing rotator may rotate a plurality of times to form a color image.

A second structure for achieving the object of the invention according to the present application is that the speed difference between the one or a plurality of image bearing rotating bodies and the transferring rotating body is ΔV ₁ , the transferring rotating body and the recording medium or When the speed difference between the other transfer rotators is ΔV ₂ , the image-bearing rotator speed, the transfer rotator speed, or the recording medium speed is set so that ΔV ₁ + ΔV ₂ = 0. An image forming apparatus according to claim 1.

A third configuration for achieving the object of the invention according to the present application is that the speed difference ΔV ₁ between the one or more image bearing rotary members and the transfer rotary member is in the range of -1% to + 1%. In
There is an image forming apparatus capable of realizing high-precision motion quality by making good use of a slip transfer mechanism and suppressing image defects such as hollow characters and improving transfer efficiency.

A fourth structure for achieving the object of the invention according to the present application is that a speed difference Δ between the transfer rotator and another transfer rotator is provided.
It is in the range V ₂ is -1% to +1%, improvement of the slip-transfer mechanism to suppress image defects such as realized with hollow-character precision motion quality due to well utilize transfer efficiency can be achieved In the image forming apparatus.

A fifth configuration for achieving the object of the invention according to the present application is that the speed difference ΔV ₃ between the transfer rotary member and the recording medium is
An image forming apparatus characterized by being in the range of -1% to + 1%, wherein the coefficient of kinetic friction between the transfer rotator and the recording medium, the coefficient of kinetic friction between the recording medium and the transfer electric field applying rotator, and the transfer rotator. The actual paper speed is determined by the speed difference between the transfer electric field applying rotary members (in this case, the transfer electric field applying rotary member receives a driving force or is driven by itself with a driving source). An image forming apparatus is characterized in that:

A sixth configuration for achieving the object of the invention according to the present application is a friction driving force acting between the transfer rotary member and the transfer electric field applying rotary member (load acting between both components and dynamic friction coefficient). The image forming apparatus is characterized in that the electric field imparting rotating body is driven by the rotation.

A seventh structure for achieving the object of the invention according to the present application is to provide a speed difference of -1% to + 1% between the transfer rotary member and the recording medium described in the sixth structure. An image forming apparatus is characterized in that a speed difference of the electric field applying rotator with respect to the transfer rotator speed is set in a range of -6% to + 6%.

An eighth configuration for achieving the object of the invention according to the present application is that a plurality of image bearing rotary members are used as one drive transmission group, and a transfer rotary member is used as another drive transmission group.
An image forming apparatus is characterized in that it has an independent drive transmission configuration. According to the above-described configuration, an image forming apparatus is characterized in that each component group can independently set a speed, and a necessary appropriate speed difference can be set freely.

A ninth configuration for achieving the object of the present invention according to the present application is to change the rotational speed command frequency to the drive motors of the plurality of drive transmission groups in the seventh configuration.
An image forming measure characterized in that a speed difference can be set arbitrarily.

The tenth aspect of the present invention to achieve the object of the invention
Is an image forming apparatus characterized in that the speed difference can be arbitrarily set by changing the acceleration / deceleration ratio of the acceleration / deceleration mechanism of the plurality of drive transmission groups in the seventh configuration.

An eleventh invention for achieving the object of the invention according to the present application
The configuration of the plurality of image bearing rotating body, the drive transmission system for integrally driving the transfer rotating body with one drive source,
An image forming apparatus is characterized in that a speed difference between respective components can be arbitrarily set by changing an acceleration / deceleration ratio of an acceleration / deceleration mechanism.

The twelfth invention for achieving the object of the invention according to the present application is described below.
The drive transmission reduction mechanism is composed of a gear train, and the speed difference between the components can be arbitrarily set by changing the number of gear teeth by changing the shift coefficient without changing the inter-gear distance. Image forming apparatus.

The thirteenth aspect which achieves the object of the invention according to the present application.
The drive transmission / reduction mechanism section is composed of a belt row, and the speed ratio between the component groups is arbitrarily set by setting the acceleration / deceleration ratio according to the ratio of the diameter of the pulley provided on each of the component body shaft portions. The image forming apparatus is characterized in that it can be set.

The fourteenth aspect of the present invention that achieves the object of the invention.
As a drive transmission belt used in the acceleration / deceleration mechanism comprising the above-mentioned belt row, a metal or a flexible or elastic flat belt, a toothed belt, a metal flat belt with holes and a pulley surface at regular intervals. An image forming apparatus using an acceleration / deceleration mechanism based on a combination with an embedded spherical tooth.

[0035]

As described above, as an effect for achieving the object of the invention according to the present invention, in particular, the advantage of slip transfer in a tandem type image forming apparatus is aimed at suppressing image quality defects and improving transfer efficiency by utilizing the advantages of slip transfer. Is characterized in that a speed difference is provided between respective components for image formation. However, in the case of the image forming apparatus according to the present invention, there are at least two or more transfer steps that affect the expansion and contraction of the image, and the amount of expansion and contraction is considerably large. The point of the operation according to the present invention is to cancel the expansion and contraction of these images as an image forming process, and to obtain stable high-precision motion quality without requiring a complicated input image signal algorithm.

[0036]

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

Embodiment 1 FIG. 1 shows a tandem-type full-color image forming apparatus as an image forming apparatus according to an embodiment of the present invention.

As shown in FIG. 1, this full-color image forming apparatus includes four photosensitive drums (image bearing rotary members) 10 for yellow (Y), magenta (M), cyan (C), and black (K). , 20, 30, 40, and these photosensitive drums 1
Primary charging charging rolls (contact type charging devices) 11, 21, 31, 41 contacting with 0, 20, 30, 40, a laser optical unit (exposure device) 50, and developing devices 12, 22, 32, 42 And above 4
Two photoconductors out of one photoconductor drum 10, 20, 30, 40
First intermediate transfer drum (transfer rotator) that comes into contact with 10 and 20
A second intermediate transfer drum (transfer rotator) 62 in contact with 61 and the other two photoconductors 30 and 40; and a third intermediate transfer drum in contact with the first and second intermediate transfer drums 61 and 62 The main part is constituted by a (transfer rotating body) 63 and a transfer electric field applying roll (transfer electric field applying rotating body) 71 which comes into contact with the third intermediate transfer drum 63. Reference numerals 13, 23, 33, and 43 denote cleaners for cleaning the surfaces of the photosensitive drums 10, 20, 30, and 40.

The photosensitive drums 10, 20, 30, and 40 are arranged at regular intervals so as to have a common tangent plane. Further, the first intermediate transfer drum 61 and the second intermediate transfer drum 62 have respective rotating shafts of the photosensitive drums 10, 20, 30, 40.
They are arranged so as to be parallel to the axis and have a plane target relation with a predetermined target plane as a boundary. Further, the third intermediate transfer drum 63 is arranged so that the rotation axis is parallel to the photosensitive drums 10, 20, 30, and 40.

The signal corresponding to the image information for each color is rasterized by an image processing unit (not shown) and input to the laser optical unit 50. Laser optical unit
At 50, the laser beams LB-Y, LB-M, LB-C, and LB-K of yellow, magenta, cyan, and black are separated and irradiated on the photosensitive drums 10, 20, 30, and 40 of corresponding colors. .

An image forming process for each color by a known electrophotographic method is performed around each of the photosensitive drums 10, 20, 30, and 40. First, as shown in FIG. 1, the surface of the photosensitive drums 10, 20, 30, and 40 is applied to a charging roller 11, 21, 31, 41 as a contact-type charging device by applying a voltage of about -1000V. , For example, to about -500V. afterwards,
On the surfaces of the photoconductor drums 10, 20, 30, and 40, laser beams LB-Y and LB-Y corresponding to yellow, magenta, cyan, and black, respectively, are irradiated by a laser optical unit 50 as an exposure device.
The LB-M, LB-C, and LB-K are irradiated to form an electrostatic latent image corresponding to the input image information for each color. Photoconductor drum 10, 20, 3
In the cases 0 and 40, when the electrostatic latent image is written by the laser optical unit 50, the surface potential of the image exposure portion is eliminated to about -100 V or less.

In this embodiment, the developing device
12, 22, 32, and 42 are a developing roll 131 and a developer conveying member 132.
And a magnetic brush contact type two-component developing system including an auger 133 for conveying and stirring the developer. The amount of the developer conveyed to the developing unit by the developing roller 131 is regulated to, for example, about 30 to 40 g / m ² by a developer amount regulating member (not shown).
The amount of charge of the toner present on the upper side is generally about -20 to 30 .mu.C / g. The developing devices 12, 22, 32, and 42 have, for example, AC +
The development is performed by applying a DC development voltage. The development voltage is 4 kHz for AC, 1.6 kVpp, and about -230 V for DC.

Further, the first and second embodiments used in this embodiment
The intermediate transfer drums 61 and 62 are cylindrical rotating bodies having a single-layer or multiple-layer surface with flexibility or elasticity. As shown in FIG. A low resistance elastic rubber layer 61b, 62b (R = 10 ² to 10 ³ Ω) typified by conductive silicone rubber or the like is provided on a metal pipe 61a, 62a as a metal core made of Is provided. Further, the outermost surfaces of the first and second intermediate transfer drums 61 and 62 are typically made of a high release layer 61c having a thickness of 20 to 25 μm made of fluoro rubber in which fluoro resin fine particles are dispersed.
It is formed as 62c (ρ _V = 10 ¹¹ to 10 ¹³ Ω · cm), and is bonded with silane coupling agent-based adhesives 61d and 62d (primer). The overall hardness of the first and second intermediate transfer drums 61 and 62 has flexibility and elasticity of about 35 to 40 degrees in JIS-A hardness.

The toner images of the respective colors formed on the photosensitive drums 10, 20, 30, and 40 are first and second in the transfer nip area.
The electric field is transferred onto the first and second intermediate transfer drums 61 and 62 by a transfer voltage of about +400 V applied to the core portions 61a and 62a of the second intermediate transfer drums 61 and 62. In FIG.
First, a magenta toner image is transferred from the photosensitive drum 20 for magenta onto the first intermediate transfer drum 61,
Next, the yellow toner image is transferred to the photosensitive drum for yellow.
From 10, the image is superimposed and transferred from above the previously transferred magenta toner image. On the second intermediate transfer drum 62, first, a black toner image is transferred from the black photosensitive drum 40, and then a cyan toner image is transferred from the cyan photosensitive drum 30 first. The transferred black toner image is superimposed and transferred from above. In one embodiment according to the present invention shown in FIG. 1, the process distance from the formation of the electrostatic latent image to the transfer of the full-color toner image to the paper is different for each color. Therefore, in the embodiment of FIG. 1, since the image is written by the laser beam in the order of the magenta image, the yellow image, the black image, and the cyan image, the first intermediate transfer drum 61 and the second intermediate transfer drum
The order of the toner images to be superimposed on 62 is determined.

As described above, the first and second intermediate transfer drums 6
After the toner images formed on the first and second intermediate transfer drums 63 are collectively transferred from the first intermediate transfer drum 61 to the third intermediate transfer drum 63 in the order of yellow and magenta, From 62, cyan and black are collectively transferred in order.

The cross-sectional structure of the third intermediate transfer drum 63 is
The first and second intermediate transfer drums 61 and 62 are substantially the same as
e or about several mm on a metal core made of Al, etc.
Low resistance elastic rubber layer (R = 10^Two~Ten^ThreeΩ), but typically
A conductive silicone rubber or the like is provided. Furthermore, the third
The outermost layer of the intermediate transfer drum 63 is typically made of fluorine
Fluororubber with dispersed fine oil particles is about 10-40μm thick
High release layer (ρ_V= 10 ¹¹~Ten¹²Ω · cm)
Adhesion with silane coupling agent-based adhesive (primer)
Have been. The hardness of the entire third intermediate transfer drum 63 is JIS-
A It has flexibility and elasticity with hardness of about 60 to 67 °.

At the transfer nip portion of the second intermediate transfer drum 62, the yellow and magenta layers previously transferred from the first intermediate transfer drum 61 are collectively transferred on the magenta layer in the order of cyan and black. A toner layer is formed in the order of yellow, magenta, cyan, and black. A transfer voltage of about +800 V is applied to the core portion of the third intermediate transfer drum 63, and the toner image on the first intermediate transfer drum 61,
The toner image on the second intermediate transfer drum 62 is transferred in a superimposed state.

On the other hand, the recording paper 72 as a recording medium is first sent by a feed roll 75 while being separated from a storage cassette 73 by a meniscus 74 for releasing the paper, and is pre-pressed by a standby roll 77 via a transport roll 76. Form a desired amount of paper curl at the nip and wait.

In response to a timing signal from a sequence controller (not shown), the recording paper 72 is conveyed from the standby roll 77 so that the leading edge of the paper coincides with the leading edge of the image. Enter the nip area with 71. The full-color toner image formed on the third intermediate transfer drum 63 is conveyed in the direction of arrow 78 while being transferred onto the recording paper 72 by the transfer voltage applied to the electric field applying roll 71, approximately + 2050V.

The transfer electric field applying roll 71 is a flexible or elastic cylindrical rotary member, and receives a driving force from the third intermediate transfer drum 63 via a gear or a third intermediate transfer drum. It is rotated by the driven by the friction driving force with the drum 63.

The toner image transferred onto the recording paper 72 by the electric field applying roll 71 is conveyed in the arrow direction 78, fixed by a fixing device (not shown), and discharged outside the apparatus. The electric field applying roll 71 is rotated in the direction of rotation while the toner adhered or transferred to the surface thereof is cleaned by the cleaner 81 and is prepared for the next transfer step.

Third intermediate transfer drum 63 and electric field applying roll
After the transfer at the transfer nip portion 71, the residual toner is electrostatically or physically removed by the cleaner 82. The cleaner 82 is a conductive roll having a rotating cylindrical shape and a resistance of about ρ _V = 10 ² to 10 ³ Ω · cm. Applied voltage is about +1200
A voltage of about V is applied to electrostatically attract and remove the residual toner.

Similarly, the first and second intermediate transfer drums 61 and 6
2 is also provided with cleaners 83 and 84, and a given voltage of about +800 V is applied. The residual toner after the secondary transfer performed between the first and second intermediate transfer drums 61 and 62 and the third intermediate transfer drum 63 is removed by electrostatic and physical sliding friction. The material of the cleaners 83 and 84 is a cylindrical conductive roll having a ρ _{V of} about 10 ² to 10 ³ Ω · cm, like the cleaner.

As described above, in FIG. 1, which is an embodiment of the present invention, the photosensitive drums 10, 20, 20 for each color are shown.
The yellow photoconductor drum 10 and the magenta photoconductor drum 20 are in contact with or close to the first intermediate transfer drum 61. Here, primary transfer from the photosensitive drums 10 and 20 to the first intermediate transfer drum 61 is performed. The first intermediate transfer drum described above
61 and the second intermediate transfer drum 62
Are parallel to the axis and are plane-symmetric with respect to a predetermined plane of symmetry.

Further, the third intermediate transfer drum 63 is provided with the first intermediate transfer drum 63.
The first intermediate transfer drum 61 and the second intermediate transfer drum 62 are disposed in contact with or close to a boundary position symmetrical with respect to the positional relationship between the intermediate transfer drum 61 and the second intermediate transfer drum 62. The secondary transfer to the third intermediate transfer drum 63 is performed.

Finally, tertiary transfer from the third intermediate transfer drum 63 to the recording paper 72 conveyed by the electric field applying roll 71 is performed, and a final full-color toner image is formed.

As described above, the transfer step according to the present invention is performed three times in the case of the embodiment shown in FIG. 1, and the transfer step which affects the expansion and contraction of the toner image by the slip transfer described above is included. Are the primary and secondary transfer steps. The third step does not occur as a color shift because all the colors have already been superimposed on the third intermediate transfer drum 63. However, since the slip transfer transfer is performed in the primary and secondary transfer as described above, the speed difference between these image forming carriers directly affects the expansion and contraction of the toner image.

[0058] The present invention has been made in view of this point, the photosensitive member and the first, the speed difference between the second transferring member [Delta] V _1, first,
The speed difference between the second transfer rotator and the third transfer rotator is ΔV
₂ , the speed of each component is set so that the signs of the speed difference ΔV ₁ and the speed difference ΔV ₂ are different.
If the speed of each component is set so that ₁ + ΔV ₂ = 0, no color misregistration occurs in the transfer process of the present invention.

FIG. 3 is a perspective view showing a driving device of the tandem type full-color image forming apparatus constructed as described above. This driving device is composed of a driving system that transmits driving force by one motor and an integrated gear train.

DC brushless motor, stepping
A drive motor 91 typified by a motor is fastened to a shaft end of the third intermediate transfer drum 63 by a flexible coupling (not shown), and directly drives the third intermediate transfer drum 63 to rotate. Then, from the third intermediate transfer drum 63 to the plurality of photosensitive drums 10, 20, 30, 40, the first and second
The driving force is transmitted to the intermediate transfer drums 61, 62, and the photosensitive drums 10, 20, 30, 40 and the first and second intermediate transfer drums 61, 62 are simultaneously rotated. Third intermediate transfer drum
On the shaft of 63, a gear 92 for transmitting drive to other components is further mounted.
Gears 93 and 94 for driving the first and second intermediate transfer drums 61 and 62 are meshed with each other.
4, the gears 95, 96, 97, 98 for driving the photosensitive drums 10, 20, 30, 40, respectively, are sequentially meshed with each other, so that the driving force is transmitted.

In the case of the drive transmission system shown in FIG. 3, the distance between the components (center-to-center distance) has a predetermined value according to a request from the process, and cannot be freely changed. Therefore, to change the speed differences ΔV ₁ and ΔV ₂ , that is, to change the number of gear teeth, it is necessary to respond by changing the transposition coefficient. here,
The question is how to estimate the proper backlash when the dislocation coefficient is changed. Usually, 60-120μ is required to ensure high-precision motion quality.
In the case of the configuration of FIG. 2 in which the backlash must be set to about m and the distance between the axes cannot be adjusted, it is necessary to repeat the trial production while comparing the dislocation coefficient with the actual motion quality data. If the amount of the backlash is too large or too small, banding occurs remarkably. The gear used here is a spur gear, a helical gear, or the like.

In the tandem-type full-color image forming apparatus according to this embodiment having the above-described configuration, it is possible to suppress the expansion and contraction of the image due to the transfer by the slip transfer method as described below. It is possible to suppress the shift of the toner image of each color due to the transfer process more than once.

That is, in the tandem type full-color image forming apparatus according to this embodiment, as shown in FIG. 1, yellow, magenta, cyan, and black photosensitive drums 10, 20, 30, and 40 have yellow, Magenta, cyan, and black toner images are formed at a predetermined timing. Among the photosensitive drums 10, 20, 30, and 40, the yellow and magenta toner images formed on the photosensitive drums 10 and 20 are the first intermediate transfer drum 61 in the order of magenta and yellow. The primary transfer is performed thereon. The cyan and black toner images formed on the photosensitive drums 30 and 40 are primarily transferred onto the second intermediate transfer drum 62 in the order of black and cyan.

Thereafter, the magenta and yellow toner images primary-transferred onto the first intermediate transfer drum 61 and the black and cyan toner images primary-transferred onto the second intermediate transfer drum 62 The toner image is transferred to the third intermediate transfer drum
It is transferred in a state of being superimposed on 63 at once.

The magenta, yellow, black and cyan toner images transferred in a state of being superimposed on the third intermediate transfer drum 63 are collectively transferred onto the recording paper 72 by the electric field applying roll 71. After the tertiary transfer, the recording paper 72 on which the magenta, yellow, black, and cyan toner images have been transferred is conveyed in the direction of the arrow and subjected to a fixing process by a fixing device (not shown). A full-color image is formed.

In this embodiment, the photosensitive drums 10, 20, 30, 40 and the first and second intermediate transfer drums 6 are used.
[Delta] V ₁ the speed difference between 1,62, first, and second intermediate transfer drum 61, 62 the speed difference between the third intermediate transfer drum 63 [Delta] V ₂
, The signs of the speed difference ΔV ₁ and the speed difference ΔV ₂ are set to be changed, and the speed of each component is set so that ΔV ₁ + ΔV ₂ = 0.

Therefore, each photosensitive drum 10, 20, 30, 40
Speed difference Δ between the first and second intermediate transfer drums 61 and 62
Set V _1, when configured to prevent hollow character, the respective photosensitive drums 10, 20, 30, 40 and the first, the speed difference [Delta] V ₁ between the second intermediate transfer drum 61, an image Of the first, second, and third
The intermediate transfer drum 61 and 62 between the third intermediate transfer drum 63, the speed difference [Delta] V ₁ and the sign is set different speed difference [Delta] V _2, first, second intermediate transfer drum 61, When the toner image is transferred from 62 to the third intermediate transfer drum 63,
Image shrinkage (or elongation) occurs to offset image elongation (or shrinkage). Accordingly, the final toner image transferred onto the third intermediate transfer drum 63 is an appropriate image without image expansion, contraction, and color shift, and a high-quality full-color image or an image of a desired color is obtained. be able to.

Next, the inventors of the present invention set each photosensitive drum 10,
The speed difference ΔV ₁ between 20, 30, 40 and the first and second intermediate transfer drums 61 and 62, and the first and second intermediate transfer drums 61 and 62
An experiment was conducted to confirm how much the speed difference ΔV ₂ between the first and third intermediate transfer drums 63 can be set to form a good image.

FIG. 4 is a schematic diagram showing a state where a toner image is transferred from the photosensitive drum to the first intermediate transfer drum.
As described above in equation (1), while the toner image 45 passes through the nip width W formed between these components at the average speed V ₀ and the time t _n , (V _PR -V _R ) · t _n Is affected by expansion and contraction.

[0070] photosensitive drum 10 5 moving at velocity V _PR
The toner image 45-1 formed on the first intermediate transfer drum 61
The difference between the velocity V _R of the toner image 45-1 on the photosensitive drum 10 while slipping Transfer transfer is made is extended (or contracted) becomes a toner image 45-2.

The expansion / contraction of the toner image due to the slip transfer is caused by the primary transfer and the secondary transfer.

FIG. 6 shows the result of evaluating the expansion and contraction of an image with actual print samples by changing the speed difference with respect to thickening of a line when a 1-bit horizontal line is formed at a resolution of 600 dpi. is there. In this example, the _thickness of the line when the speed difference is provided in the slip transfer from the photosensitive member to the intermediate transfer belt in the relationship of V _IBT > V _PR is shown. According to this result, the line thickness is not noticeable when it is within approximately 1%, but it can be seen that the line starts to thicken rapidly when the speed difference exceeds that.

FIG. 7 shows the change in the expansion and contraction of the image when the ideal slip transfer transfer is performed, when the speeds of the first and second transfer rotating members are varied with respect to the speed of the photosensitive member. . The image expansion / contraction does not depend on the geometrical eccentricity of the photoreceptor, the difference in the average angular velocity, and the difference in the photoreceptor diameter, and the first and second intermediate transfer drums (transfer rotating body) with respect to the photoreceptor speed ) Changes almost linearly with the speed ratio. Therefore, for example, in the case of a speed difference setting in which + 1% elongation occurs in the primary transfer, it should be set so that a contraction of -1% occurs in the secondary transfer.

FIG. 8 shows the correlation between the speed difference between the photoreceptor and the intermediate transfer belt, which is related to the phenomenon of a central portion of a character or the like, that is, a so-called hollow character. Generally speaking,
For example, in an image forming apparatus using an intermediate transfer belt, 2
In the next transfer section, the applied load between the bias transfer roll and the intermediate transfer belt acts as an external force to increase the cohesion between toners,
In addition, the external force also increases the adhesive force between the intermediate transfer belt and the toner. Originally, we want to sufficiently increase the adhesive force between the paper surface and the toner. However, the paper surface has irregularities ranging from several tens of μm to 100 and several tens of μm. It is said that an insufficient suction force is not sufficiently increased, and an image omission phenomenon particularly occurs at the center of a line image such as a character.

If such a hollow character generation mechanism is provided with a speed difference between the constituent elements, as shown in FIG. 9, the cohesive force f ₂ between the toners can be reduced,
Shearing force acts in a direction that reduces the adhesion f ₁ between the intermediate transfer belt and the toner, if the adhesion between the paper and the toner was f _3, meet consequently f _2> f ₃ »f ₁ the relationship Each force acts in the direction, and it becomes possible to suppress the generation of a hollow character.

FIG. 10 shows how the speed of the conveyed paper depends on the speed of the electric field applying roll. In the transfer process, the speed of the sheet relative to the surface speed of the third intermediate transfer drum (transfer rotating body) is substantially known. That is, the allowable range of the paper speed with respect to the surface speed of the third intermediate transfer drum (transfer rotating body) is as shown in FIG.
It is almost known as shown on the vertical axis of zero. Next, it can be seen from FIG. 10 that the electric-field-applying roll speed for achieving the proper paper speed range can be almost realized if it is in the range of -6% to + 6%. This is because the dynamic friction coefficient between the surface of the electric field applying roll and the back of the paper and the transport force and slip due to the nip load, and the dynamic friction coefficient between the paper surface and the intermediate transfer belt surface and the transport force and the slip due to the nip load are complicatedly related. Paper speed is determined.

Second Embodiment FIG. 11 shows a second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals and described. The image bearing rotator and the transfer rotator are independently driven as unit components. The speed of the unit components is set by a rotation speed command frequency to a drive motor arranged in each component.

FIG. 11 shows an embodiment of an independent drive type in which each component is divided into several drive transmission groups and the speed is set in each group.

First, a plurality of photosensitive drums 10, 20, 30, 40
A group consisting of gears 101, 102, 103, 104 provided on each shaft, idle gears 105, 106, 107 for drive connection and a drive motor 108, and gears 109, 110 provided on the shafts of the first and second intermediate transfer bodies 61, 62. A group consisting of an idle gear 111 and a drive motor 112 for driving connection;
3 consisting of a group of drive motors 113 fastened to the shaft of the intermediate transfer member 63 by a flexible coupling (not shown).
Drive transmission group.

In this independent drive type embodiment, there are two ways to change the speed setting of each component. One is means for changing the rotation speed of the motor itself by changing the rotation speed command frequency to each of the drive motors 105, 109, 110, and the other is gears 109, 110 provided on the shafts of the first and second intermediate transfer bodies 61, 62. Idle gear 111 for drive connection
The speed increase / decrease ratio is set to a desired speed difference, or the gears 110, 102, 103, 104 provided at the ends of the respective photosensitive drums 10, 20, 30, 40 and the respective idle gears 105,
There are two types of means for setting the speed difference by changing the speed increasing / decreasing ratio in the transmission unit, such as setting the speed increasing / decreasing ratio between 106 and 107 to be a desired speed difference.

FIG. 12 shows the difference in the method of transmitting the drive from the third intermediate transfer drum to the charge applying roll.
Indicates the use of friction drive, and (b) indicates the use of gear drive transmission. In the case of the gear drive transmission, a gear 120 is provided at the end of the third intermediate transfer drum 63, and a gear 121 that meshes with the gear 120 is provided at the side end of the electric field applying roll 71. I have.

Although the toner image expands and contracts due to the slip transfer in the tertiary transfer, the entire image expands and contracts together with the toner images of the respective colors, so that no color shift occurs. Of the third transfer nip portion, or influence (banding) on motion quality from the third transfer rotating body to the process upstream side.

The electric field applying roll 71 has springs 12 at both ends.
2,123, and the third intermediate transfer drum 63
An appropriate load is applied to the transfer nip between the roller and the electric field applying roll 71.

Third Embodiment FIG. 13 shows a third embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals and described. The accelerating / decelerating mechanism is composed of a belt row, and is configured to be set by the ratio of the diameter of the pulley provided on each unit component shaft. The drive transmission belt used in the speed increasing / decreasing mechanism composed of the above-described belt row is a metal or a flexible or elastic flat belt, a toothed belt, a metal flat belt with holes, and embedded at regular intervals on the pulley surface. An acceleration / deceleration mechanism based on a combination with the set spherical teeth is used.

FIG. 13 shows another embodiment of a drive transmission system using a flat belt and a pulley. 50-300 μm thickness
A metal flat belt typified by SUS having a width of about 5 to 50 mm is used, and a metal pulley made of Al, Fe, SUS, or the like, or a resin pulley typified by POM, PC, or the like is used.

The drive motor 131 is used to drive the third intermediate transfer drum.
The driving force is supplied to the gear 132 and the main pulley 133 by a flexible coupling (not shown) fastened to the shaft portion 63.
Is transmitted to The main pulley 133 is for each photosensitive drum 1
Idle pulley 13 with drive transmission to 0, 20, 30, 40
4,135,136 and the core portion (typically, Al is used) at the end of the photoreceptor are directly and alternately stretched. Although not shown here, the driving flat belt 137 is provided with a tension mechanism for applying and releasing a tension, and an appropriate tension is applied.

On the other hand, the reduction gear 13 meshing with the gear 132
A main pulley 139 for driving the first and second intermediate transfer drums 61 and 62 is fixed to the shaft 8. Similarly, a flat belt 140 is stretched via an idle pulley 141.

In the embodiment shown in FIG. 13, the speed of the third intermediate transfer drum 63 is determined by the rotation speed of the drive motor 131, and the speed of each of the photosensitive drums 10, 20, 30, and 40 is determined by the pulley 133.
Is determined by the ratio between the diameter of the photoconductor and the diameter of the pulleys 134, 135, and 136 provided at the end of the photoconductor, or the ratio of the diameter of the core at the end of the photoconductor. The speed of the first and second intermediate transfer drums 61 and 62 is determined by the meshing ratio between the gear 132 and the reduction gear 138. That is, in the embodiment of FIG. 13, the speed difference between the components can be arbitrarily changed by changing the diameter of the pulley involved.

FIG. 14 shows an embodiment of the drive transmission diameter of the toothed belt and the toothed pulley. This is basically the same as the case of the flat belt and the pulley shown in FIG.

FIG. 15 shows an embodiment of a drive transmission system using a perforated flat belt and a pulley having spherical teeth.
The concept of changing the speed difference between the components is the same as that described above. It can be said that the feature of this drive transmission system is a drive unit that achieves both good driving of the flat belt and good gear driving. In the case of the flat belt drive shown in FIG. 13, the load of the system to be rotated or the slip with the pulley occurs as a problem when the system has a large fluctuation. This directly appears as color misregistration and negates the advantage that handing does not occur as in the gear drive transmission system.

FIG. 14 shows a drive transmission system using a toothed belt and a toothed pulley. Although a core body for increasing rigidity such as urethane is provided as an intermediate layer as a material of the belt, this is also a load of the target system. Or, if the fluctuation is large, the belt is stretched and contracted. In addition, it is known that the speed of this type of toothed belt is determined by the position of the high-rigidity core body in the belt thickness direction, but there is a tendency that it is difficult to manufacture the belt with high accuracy in the thickness direction.

On the other hand, in FIG. 15, the meshing banding caused by the meshing of the gears can be reduced, and the spherical teeth embedded in the pulley mesh with the perforated portion of the belt, so that the load on the target system increases and changes. However, the high-precision MQ can be secured.

FIG. 16 shows a perforated belt attached to the toothed pulley 146-1.
147 shows a state where the perforated portions 151 are engaged. As the belt material, SUS301, SUS304, SUS631, 15-7PH, titanium or the like can be appropriately selected, and the belt may be selected in the range of 50 to 300 μm in thickness and 5 to 300 mm in width. Regarding the material of the pulley 146-1 and the spherical teeth 152, as an example, φ3m
For example, an SKS-21 (hardened) sphere 152 having a size of about m is equally divided by 30 ° and about half of the sphere is embedded.

[0094]

As described above, according to the present invention, in an image forming apparatus having a transfer process in which image expansion and contraction due to slip transfer is predicted twice or more, mutual image expansion and contraction are achieved. 1 to cancel
By setting the speed difference in the next or secondary transfer section, the expansion and contraction of the image in the process can be canceled with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional configuration diagram illustrating an intermediate transfer drum of the image forming apparatus according to Embodiment 1 of the present invention.

FIG. 3 is a diagram illustrating an embodiment in which a plurality of image carriers and a transfer rotating body according to the present invention are driven by one motor and an integrated gear train.

FIG. 4 is a cross-sectional view schematically illustrating a state in which a toner image on a photoconductor is transferred at a nip portion between the photoconductor and a first intermediate transfer drum.

FIG. 5 is a diagram schematically illustrating a state in which a toner image on a photoconductor is stretched when the toner image on the photoconductor is transferred onto a first intermediate transfer member due to a speed difference in a nip portion.

FIG. 6 is a diagram showing a correlation between a speed difference in a nip portion and expansion / contraction of an image.

FIG. 7 is a diagram showing changes in expansion and contraction of an image on a sample when the average speed of the first and second intermediate transfer drums is changed.

FIG. 8 is a diagram showing a correlation between a speed difference in a nip portion and a hollow character level.

FIG. 9 is a schematic diagram illustrating a transfer mechanism in a nip portion.

FIG. 10 is a diagram showing how the paper speed changes with respect to the third intermediate transfer member when the speed of the electric field applying roll with respect to the third intermediate transfer member is changed.

FIG. 11 shows a plurality of photoconductor groups (c), first and second intermediate transfer body groups (b), and third photoconductor groups (c) according to Embodiment 2 of the present invention.
FIG. 5 is a diagram showing a drive system that is driven by being divided into an intermediate transfer body group (a) and three drive transmission groups.

FIG. 12 shows a difference in a drive transmission system from a third intermediate transfer body to a transfer electric field applying roll. FIG. 12 (a) uses friction drive between the third intermediate transfer body and the transfer electric field applying roll. FIG. 10B is a diagram illustrating a state in which the drive is transmitted from a gear provided at the end of the third intermediate transfer member to an end of the electric field applying roll.

FIG. 13 is a diagram illustrating a drive transmission system including a flat belt and a pulley according to a third embodiment of the present invention.

FIG. 14 is a diagram illustrating a drive transmission system including a toothed belt and a toothed pulley.

FIG. 15 is a diagram illustrating a drive transmission system including a perforated flat belt and a pulley having spherical teeth.

FIG. 16 is a cross-sectional view showing engagement between the perforated flat belt of FIG. 15 and a pulley having spherical teeth.

[Explanation of symbols]

10, 20, 30, 40 Yellow, magenta, cyan, black photosensitive drum (image bearing rotating body) 11, 21, 31, 41 yellow, magenta, cyan, black charging roll 12, 22, 32, 42 yellow, magenta, Cyan, black developing unit 13, 23, 33, 43 Yellow, magenta, cyan, black cleaner 50 Laser optical unit 61 First intermediate transfer drum (transfer rotator) 62 Second intermediate transfer drum (transfer rotator) 63 No. 3 intermediate transfer drum (transfer rotating body) 71 Transfer electric field applying roll (transfer electric field applying rotary body) LB-Y, LB-M, LB-C, LB-K Yellow, magenta, cyan, and black laser beams 131 Developing roll 132 Developer conveying member 133 Stirring auger 61a, 62a Metal pipe 61b, 62b Low resistance elastic rubber layer 61c, 62c High release layer 61d, 62d Adhesive 81 Cleaner 82 Cleaner 83,84 Cleaner 91 Drive motor 92 Third intermediate transfer drum 93,94 Gears for driving the first and second intermediate transfer drums 95,96,97,98 Gears for driving each photosensitive drum 45 Toner image 45-1 Photosensitive Toner image formed on body drum 45-2 Expanded (or contracted) toner image 101, 102, 103, 104 Gears 105, 106, 107 provided on shafts of a plurality of photosensitive drum groups Idle gear 108 for drive connection 108 Drive motors 109, 110 First, Gear 111 provided on the shaft of the second intermediate transfer member 111 Idle gear for drive connection 112 Drive motor 113 Drive motor 132 Drive gear of third intermediate transfer drum 133 Main pulley 134,135,136 Idle pulley 137 Driving flat belt 138 Reduction gear meshing with gear 132 139 Main pulley 140 Flat belt 141 Idle pulley

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kiichiro Iijima 430 Sakai-Nakai-cho, Ashigara-gun, Kanagawa Prefecture Green Tech Nakai Fuji Xerox Co., Ltd. F-term (reference) 2H030 AA01 AB02 AD16 BB02 BB23 BB42 BB46 BB53 2H032 AA05 AA15 BA01 BA08 BA23 2H071 CA01 CA03 CA05 CA07 CA09 DA08 DA09 DA15 DA27

Claims (16)

[Claims] 1. A method for forming a latent image corresponding to input information for each color, developing the latent image with a toner of a corresponding color to obtain a plurality of single-color toner images, An image forming apparatus that forms a color image by being fixed thereon, wherein each latent image is formed according to input information for each color, and each latent image is developed with a toner of a corresponding color to form a single color toner. 3 arranged to have a common tangent plane on which the image is formed
More than one image-bearing rotator, or a single latent image corresponding to the input information for each color is sequentially formed, and each latent image is developed with a corresponding color toner to form a single-color toner image sequentially. An image bearing rotating body, one or a plurality of transferring rotating bodies arranged to be in contact with or close to the image bearing rotating body, and to which each single color toner image formed on the image bearing rotating body is transferred; A transfer electric field applying rotator for transferring a toner image transferred onto one or more transfer rotators to a recording medium, and forming a color image through at least two or more toner image transfer steps. In the image forming apparatus, when the speed difference between the image bearing rotator and the transfer rotator is ΔV ₁ , and the speed difference between the transfer rotator and another transfer rotator or recording medium is ΔV ₂ , the speed difference ΔV
An image forming apparatus, wherein the speed of the image bearing rotary member, the speed of the transfer rotary member, or the speed of a recording medium is set such that the sign of the speed difference ΔV ₂ differs from ₁ . 2. When the speed difference between the image bearing rotator and the transfer rotator is ΔV ₁ , and the speed difference between the transfer rotator and another transfer rotator or recording medium is ΔV ₂ , ΔV ₁ + ΔV
_2. The image forming apparatus according to claim 1, wherein the speed of the image bearing rotating body, the speed of the transferring rotating body, or the speed of the recording medium is set so that ₂ = 0. 3. The image forming apparatus according to claim 2, wherein a speed difference between the image bearing rotating body and the transfer rotating body is in a range of | ΔV ₁ | <1%. 4. The image forming apparatus according to claim 2, wherein a speed difference between the transfer rotator and another transfer rotator is in a range of | ΔV ₂ | <1%. 5. A speed difference Δ between the transfer rotator and a recording medium.
_3. The image forming apparatus according to claim 2, wherein V ₃ is in the range of | ΔV ₃ | <1%. 6. The image forming apparatus according to claim 2, wherein there is no speed difference ΔV ₄ between the transfer rotator and the transfer electric field applying rotator. 7. The image forming apparatus according to claim 2, wherein a speed difference ΔV ₄ between the transfer rotator and the transfer electric field applying rotator is in a range of | ΔV ₄ | <6%. 8. A latent image corresponding to input information for each color is formed, and each latent image is developed with a toner of a corresponding color to obtain a plurality of single-color toner images. An image forming apparatus that forms a color image by being fixed thereon, wherein each latent image is formed according to input information for each color, and each latent image is developed with a toner of a corresponding color to form a single color toner. 3 arranged to have a common tangent plane on which the image is formed
More than one image-bearing rotator, or a single latent image corresponding to the input information for each color is sequentially formed, and each latent image is developed with a corresponding color toner to form a single-color toner image sequentially. An image bearing rotating body, one or a plurality of transfer rotating bodies arranged in contact with or in close proximity to the image bearing rotating body, and each of the monochromatic toner images formed on the image bearing rotating body being transferred; A transfer electric field applying rotator for transferring a toner image transferred onto one or more transfer rotators to a recording medium, and forming a color image through at least two or more toner image transfer steps. 3. The image forming apparatus according to claim 1, wherein the image bearing rotator and the transfer rotator are independently driven as unit components. 4. 9. The apparatus according to claim 1, wherein the speed of the unit structure is set by a rotation speed command frequency to a drive motor arranged in each structure. The image forming apparatus according to any one of the above. 10. The apparatus according to claim 1, wherein the speed of the unit structure is set by an acceleration / deceleration ratio of an acceleration / deceleration mechanism in each drive transmission system. An image forming apparatus according to claim 1. 11. A latent image corresponding to input information for each color is formed, and each latent image is developed with a toner of a corresponding color to obtain a plurality of single-color toner images. An image forming apparatus that forms a color image by being fixed thereon, wherein each latent image is formed according to input information for each color, and each latent image is developed with a toner of a corresponding color to form a single color toner. 3 arranged to have a common tangent plane on which the image is formed
More than one image-bearing rotator, or a single latent image corresponding to the input information for each color is sequentially formed, and each latent image is developed with a corresponding color toner to form a single-color toner image sequentially. An image bearing rotating body, one or a plurality of transfer rotating bodies arranged in contact with or in close proximity to the image bearing rotating body, and each of the monochromatic toner images formed on the image bearing rotating body being transferred; A transfer electric field applying rotator for transferring a toner image transferred onto one or more transfer rotators to a recording medium, and forming a color image through at least two or more toner image transfer steps. In the image forming apparatus, the image bearing rotary member and the transfer rotary member are driven by a common drive source, and the speed of the unit component is set by an acceleration / deceleration ratio of an acceleration / deceleration mechanism in a drive transmission system. Claim 1 or The image forming apparatus according to claim 2. 12. The acceleration / deceleration mechanism comprises a gear train,
12. The image forming apparatus according to claim 1, wherein the speed of the unit structure is set by a ratio of the number of meshing teeth between the unit structures. 13. The unit structure according to claim 1, wherein the speed increasing / decelerating mechanism comprises a belt row, and a speed of the unit structure is set by a ratio of a diameter of a pulley provided on each unit structure shaft. 12. The image forming apparatus according to claim 2, wherein: 14. A drive transmission belt used in the acceleration / deceleration mechanism comprising the above-mentioned belt row, a metal or a flexible or elastic flat belt, a toothed belt, a metal flat belt with holes and a fixed interval between the pulley surface. 14. The image forming apparatus according to claim 13, wherein an acceleration / deceleration mechanism based on a combination with a spherical tooth embedded in the apparatus is used. 15. The drive transmission between the transfer rotator and the transfer electric field applying rotator is performed by applying a pressure applied between the two unit components to a position between the transfer rotator surface and the transfer electric field applying rotator surface. 7. The image forming apparatus according to claim 6, wherein the drive is transmitted by a drive transmission force acting by frictional force. 16. A gear that meshes with a gear provided in the transfer rotator driving unit for driving transmission between the transfer rotator and the transfer electric field imparting rotator, is provided at an end of the transfer electric field imparting rotator. The image forming apparatus according to claim 7, wherein: