JPH02108072A - Color recorder - Google Patents

Abstract

PURPOSE:To obtain a high definition picture free of color slurring, blurring and transfer omission by forming an intermediate transfer body with a seamless belt and providing an electrostatic transfer unit for transferring a toner picture onto the intermediate transfer body on a 1st transfer part. CONSTITUTION:The electrostatic transfer unit 14 in the 1st transfer part 13 sequentially superposes and transfers toner pictures of plural colors of toner formed on a recording medium 1 on the intermediate transfer body 2 composed of the seamless belt. A carrying roller 12 heated by a heat source 15 and a pressure roller 16 brought into press-contact with the carrying roller 12 through a recording paper 100 press and heat the toner images superposed on the intermediate transfer body 2, and the pictures are transferred and fixed on the recording paper. Since toner pictures are temporarily transferred onto the intermediate transfer body 2 moving in synchronism with the recording medium, transfer positioning can be performed with high accuracy. Thus, superposed transfer free of blur and transfer omission can be accomplished.

Description

[Detailed Description of the Invention] [Summary] An object of the present invention is to provide a color recording device that records multiple colors using an electrophotographic recording method, etc., so that high-quality images without color shift, blurring, or transfer omissions can be obtained. After forming a plurality of color toner images on a recording medium and sequentially superimposing and transferring the toner images to an intermediate transfer body that moves in synchronization with the recording medium in a first transfer section, the toner images are transferred onto the intermediate transfer body. In the color recording device, the intermediate transfer member is formed of a seamless belt, and the first transfer unit includes a toner image transfer member for transferring the toner image to the intermediate transfer member. Equipped with an electrostatic transfer device,
The second transfer section is provided with a conveyance roller that conveys the intermediate transfer body, and a pressure roller that moves forward and presses against the conveyance roller during transfer and fixing, and of the conveyance roller and the pressure roller, at least the conveyance roller The roller has a built-in heat source.

[Industrial application field]

The present invention relates to a color recording device that performs recording in multiple colors using an electrophotographic recording method or the like.

(Prior Art) In an electrophotographic recording apparatus, a device that sequentially forms toner images of a plurality of colors on a recording medium such as a photoreceptor drum, and transfers the toner images onto recording paper in an overlapping manner is conventionally known. Conventional devices include the following types (1) to (4).

(1) Toner images of multiple colors are sequentially formed on one photoreceptor drum, and each toner image is transferred to recording paper each time. After all the toner images have been transferred, the recording paper is passed through a fixing device to fix the toner image on the recording paper.

As a result, a color image in which toner images of multiple colors are superimposed can be obtained.

(2) The leading edge of the recording paper is gripped by a gripper, and the recording paper is attracted to a transfer drum having a surface layer of a dielectric film or a dielectric screen mesh to perform multiple transfers.

(3) A plurality of photoreceptor drums are provided for forming toner images of a plurality of colors. Then, while the recording paper is electrostatically attracted to a transfer heald made of a dielectric film or a dielectric screen mesh and conveyed, the toner images on each photosensitive drum are sequentially superimposed and transferred onto the recording paper.

(4) A gripper grips the leading edge of the recording paper and transfers the toner images one after another while conveying the recording paper.

[Problem to be solved by the invention]

However, these conventional devices had the following drawbacks.

Case (1): After the first toner image is transferred to the recording paper, the second and subsequent toner images must be superimposed and transferred again to the same recording paper at a predetermined position, so highly accurate positioning is not possible. A possible transfer technique is needed.

Case (2): In addition to the problem that the image at the leading edge of the recording paper gripped by the gripper is missing, there is the following problem.

In other words, when a dielectric film is used for the transfer drum, the electrostatic adhesion to the paper is good and there is little color shift during overlapping transfer, but the transfer device becomes unstable in charging the paper. Blurred images and transfer defects were likely to occur. On the other hand, when a dielectric screen mesh was used, good transfer could be achieved without blurring or missing transfer images, but the electrostatic adsorption force was reduced and color shift was likely to occur.

Case (3): Since electrostatic adsorption was used, there was a problem similar to the case of item (2) above.

Case (4): The recording paper is attracted to the photosensitive drum before and after the transfer area, but since this state of attraction is not always constant, color shift is likely to occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a color recording device that can obtain high-quality images without color shift, blurring, or transfer omissions.

[Means to solve the problem]

In order to achieve the above object, the present invention forms toner images of multiple colors on a recording medium, and sequentially overlays the toner images on an intermediate transfer member that moves in synchronization with the recording medium in a first transfer section. In a color recording device, the toner image on the intermediate transfer body is transferred and fixed onto a recording paper in a second transfer section after the alignment transfer, and the intermediate transfer body is formed of a seamless belt, and the first transfer section includes: An electrostatic transfer device for transferring a toner image to the intermediate transfer body is provided, and the second transfer unit includes a conveyance roller that conveys the intermediate transfer body, and a conveyance roller that can move forward and backward in opposition to the conveyance roller, and that .

A pressure roller that moves forward and comes into pressure contact with the conveyance roller during fixing is disposed, and of the conveyance roller and the pressure roller, at least the conveyance roller has a built-in heat source.

[For production]

The toner images of multiple colors formed on the recording medium are sequentially superimposed and transferred onto the intermediate transfer body by an electrostatic transfer device in the first transfer section. The toner image superimposed on the intermediate transfer member is then pressed and heated onto the recording paper by a conveyance roller heated by a heat source and a pressure roller that presses against the conveyance roller heated by a heat source through the recording paper. Transferred and fixed.

Thus, in the present invention, unlike the conventional case described above, in which the recording paper is held by some means and the toner image is directly transferred onto it from the photosensitive drum, the toner image is moved in synchronization with the recording medium. In order to transfer the image to the intermediate transfer body,
Transfer positioning can be performed with high precision. In other words, the amount of movement will not change due to adsorption to the recording medium (
8), the contact state does not change for each color, and color misalignment will not occur.

In addition, as mentioned above, since the transfer of each color toner image to the intermediate transfer body is performed directly using an electrostatic transfer device, by controlling the transfer voltage, good overlapping transfer without blurring or transfer omissions can be achieved. It is possible.

Furthermore, the transfer and fixing of the toner image on the intermediate transfer member is reliably performed by pressure and heating using a conveyance roller and a pressure roller.

〔Example〕

The present invention will now be described in detail with reference to FIGS. 1 to 4.

A first embodiment is shown in FIGS. 1 to 3.

FIG. 1 is a side view showing an outline of the structure of a color recording apparatus according to the present invention. In the figure, 1 is a recording medium (photosensitive drum), and 2 is an intermediate transfer body.

An electrophotographic process unit consisting of a charger 3, an exposure optical system 4 using an LD (semiconductor laser) or an LED (light emitting diode) as a light source, and developers 5 to 8 is arranged around the recording medium 1. There is.

Developing device 5 contains yellow (Y) toner, developing device 6 contains magenta (M) toner, and developing device 7 contains cyan (Y) toner.
C) color toner is stored in the developing device 8, and black (K) color toner is stored in the developing device 8, respectively. 9 is a cleaner placed at a predetermined position around the recording medium 1;

The intermediate transfer body 2 is formed of a two-layer seamless belt consisting of a base material 2a and a transfer layer 2b as shown in FIG. It moves in the direction of the arrow in synchronization with the recording medium 1 which rotates in the direction of the arrow. The base material 2a is made of a material with excellent heat resistance and mechanical strength, such as a polyimide seamless belt with a thickness of 10 to 50 μm (preferably 15 to 30 μm), and the transfer layer 2b is made of a material with excellent heat resistance and mechanical strength. It is formed by coating the toner image transfer side of the base material 2a with a superior material such as a fluororesin to a thickness of 1 to 20 μm (preferably 3 to 10 μm).

The intermediate transfer body 2 has a total length that is determined by making it longer than the largest recording paper used or by taking into consideration the maximum length of the image to be recorded, and is arranged between the conveyor rollers 10 and 11.
The transfer unit 13 is arranged close to the recording medium 1 . The first transfer section 13 is provided with an electrostatic transfer device 14 that faces the recording medium 1 with the intermediate transfer body 2 interposed therebetween. The conveyance roller 12 is a heat roller and has a built-in heat source 15 such as a halogen lamp. A pressure roller 1 whose surface is lined with silicone rubber faces the conveyance roller 12.
6 is provided so that it can move forward and backward.

The pressure roller 16 is rotatably supported by one end of a lever 18 which is rotatably supported by a fulcrum 17.
A spring 19 and a solenoid 20 are connected to the other end. A second transfer section 21 is formed between these rollers 15 and 16, and the recording paper 100 is transferred to the second transfer section 21 during transfer.
It passes through the transfer section 21 and is conveyed in the direction of the arrow.

Color recording on the recording paper 100 by this apparatus is performed in the following procedure.

During recording, first, the surface of the recording medium 1 rotating in the direction of the arrow is uniformly charged by the charger 3.

Next, an electrostatic latent image is formed thereon by the optical system 4, and this latent image is developed by the Y color developer 5.

At this time, since the developing operations of the developing devices 6, 7.8 for other colors have been canceled, only the Y color is developed. The Y color toner image formed by this development is electrostatically transferred onto the intermediate transfer member 2 by an electrostatic transfer device 14 in the first transfer section 13 .

The Y color toner remaining on the recording medium 1 without being transferred is removed by the cleaner 9. During this Y color transfer, the pressure roller 16 is positioned as indicated by the dotted line by the operation of the solenoid 20 and is away from the intermediate transfer body 2, so that the Y color toner image on the intermediate transfer body 2 is transferred to the intermediate transfer body 2. The image is conveyed to the first transfer section 13 again while being held in place.

On the other hand, on the recording medium 1, M color development is performed in the same way as in the case of Y color (only the M color developing device 6 is operated), and the M color toner image is sent to the first transfer section 13. Since the intermediate transfer body 2 rotates in synchronization with the rotation of the recording medium 1, the M color toner image is positioned with high precision (within ±100 μm) with respect to the Y color toner image on the intermediate transfer body 2. The images are transferred in an overlapping state.

Similar development and transfer are performed for the 0 and 0 colors, and the toner images that are all transferred and superimposed on the intermediate transfer body 2 are conveyed to the second transfer section 21 . At the same time, the recording paper 100 is transferred to the second transfer section 2 by a paper feed roller (not shown).
1, and the pressure roller 16 is brought into pressure contact with the intermediate transfer body 2 immediately before the start of toner image transfer onto the recording paper 100. This pressure contact is performed by deactivating the solenoid 20. That is, when the solenoid 20 receives a signal and turns off, the lever 18 is biased by the spring 19 and the first
Rotating clockwise in the figure, the pressing roller 16 comes into pressure contact with the intermediate transfer body 2 as shown by the solid line.

In the second transfer section 21, as shown in FIG. 3, heat from the conveyance roller 12 is supplied through the intermediate transfer body 2 as shown by the arrow, and this heat and pressure by the pressure roller 16 cause the toner image to be formed. 101 is transferred onto the recording paper 100 at the nip (contact area).

By the way, the intermediate transfer body 2 has a small heat capacity due to its thin thickness of about 30 μm, and can be heated and cooled in a short time. Therefore, rather than providing a heat source on the pressure roller 16 on the back side of the recording paper 100 and supplying heat through the paper, as in this example, the heat source
It is more efficient to supply heat through the intermediate transfer body 2 by the conveyance roller 12 equipped with the conveyor roller 12 having the conveyance roller 12 having a conveyor roller 12 having a conveyor roller 12 having a conveyor roller 12 having a conveyor roller 12 having a conveyor roller 5. In addition, since the transfer layer 2b on the surface of the intermediate transfer body 2 is made of a material with excellent release properties, it easily peels off the molten toner and transfers the toner onto the recording paper 100.
% transfer is possible.

Note that if a heat source is additionally provided to the pressure roller 16 in order to prevent heat from being taken away by the recording paper, the heat can be supplied more effectively and the fixing performance can be improved.

As described above, in the present invention, since the toner image is once transferred to the intermediate transfer member 2 that moves in synchronization with the recording medium 1, transfer positioning can be performed with high precision.
Color shift can be prevented.

In addition, since the toner images of each color are directly transferred to the intermediate transfer body 2 using the electrostatic transfer device 14, by controlling the transfer voltage, good overlapping transfer without blurring or missing transfer can be achieved. is possible.

Furthermore, the transfer and fixing of the toner image on the intermediate transfer body 2 is carried out by a transport roller 12. This can be reliably performed by applying pressure and heating using the pressure roller 16.

FIG. 4 shows a second embodiment.

Figure 4 is a side view showing the structure and outline of the color recording device.
This color recording apparatus has a plurality of recording media (photosensitive drums) for forming toner images of multiple colors. In FIG. 4, 31a to 31d are recording media arranged in parallel at a predetermined pitch, 32a to 32d are chargers, 33a to 33d are exposure optical systems, 34a to 34d are Y,
M.

Developing devices for C and K colors, 35a to 35d are electrostatic transfer devices, 3
6a to 36d are cleaners. Further, 37 is an intermediate transfer body formed of the same material as in the previous example, and a conveyance roller 38
and the conveyance roller (heat roller) 39.
It runs in the direction of the arrow in synchronization with each recording medium that rotates at the same speed clockwise as shown by the arrow. The conveyance roller 39 has a built-in heat source 40. 41 is a pressure roller that presses against the conveyance roller 39 during transfer and fixing as in the previous example;
42a to 42d are first transfer parts, and 43 is a second transfer part.

When recording, Y,
Forms M, C, and K color toner images. Each recording medium 3
Each color toner image formed on 1a to 31d is transferred to each electrostatic transfer device 35a to 3 in each first transfer section 42a to 42d.
5d onto the intermediate transfer member 37, each of the recording media 31a to 31d is arranged side by side with a predetermined pinch, so that the toner images of each color are accurately superimposed and no color shift occurs.

The superimposed toner images are transferred and fixed onto the recording paper 1oo in the second transfer section 43 by pressure and heating by the conveyance roller 39 and the pressure roller 41.

In the case of this example, in addition to the same effects as the previous example, there is also the effect that high-speed output is possible because it has four toner image forming sections.

C Effects of the Invention] As described above, according to the present invention, toner images of multiple colors are superimposed and electrostatically transferred onto an intermediate transfer member driven in synchronization with the recording medium, and then transferred from the intermediate transfer member. Since the images are transferred and fixed onto the recording paper using heat and pressure, overlapping transfer with high positional accuracy is possible, and high-quality images can be obtained without color shifts, blurring, or missing transfers. .

[Brief explanation of the drawing]

1 is a side view showing an outline of the structure of a color recording apparatus according to a first embodiment of the present invention; FIG. 2 is a cross-sectional view showing the structure of an intermediate transfer body; and FIG. 3 is a sectional view showing a second transfer unit. Fig. 4 is a side view showing an outline of the structure of a color recording apparatus according to a second embodiment of the present invention, and in the figure, 1.31a, 31b, 31c, and 31d are recording units. medium, 2.37 is an intermediate transfer body, 12.39 is a conveyance roller, 13.42a, 42b, 42c, 42d are first transfer parts, 14, 35 a, 35 b, 35 c,
35 d is an electrostatic transfer device, 15.40 is a heat source, G 16.41 is a pressure roller, 21.43 is a second transfer section, and 100 is a recording paper.

Claims (1)

[Scope of Claims] A plurality of color toner images are formed on a recording medium (1), and the toner images are transferred to the recording medium (1) in a first transfer section (13).
) In a color recording device, the toner image on the intermediate transfer body (2) is transferred and fixed onto recording paper in a second transfer section 21 after being sequentially superimposed and transferred to an intermediate transfer body (2) that moves in synchronization with the intermediate transfer body (2). , the intermediate transfer body (2) is formed of a seamless belt, and the first transfer section (13) is provided with an electrostatic transfer device (14) for transferring the toner image to the intermediate transfer body (2). The second transfer section (21) includes a conveyance roller (12) that conveys the intermediate transfer body (2), and a conveyance roller (12) that conveys the intermediate transfer body (2).
A pressure roller (16) is disposed that can move forward and backward in opposition to the transfer roller (16) and moves forward to press against the conveyance roller (12) during transfer and fixing, and among the conveyance roller (12) and the pressure roller (16), A color recording apparatus characterized in that at least a conveyance roller (12) has a built-in heat source (15).