JPS60158475A - Multiple-image recording method - Google Patents

Abstract

PURPOSE:To enable stable and satisfactory multiple-image recording by repeating formation of a magnetic image and development in which a developer layer is not brought into direct contact with an image forming body. CONSTITUTION:The surface of an image forming body 1 is treated by a destaticizer 11, a cleaning device 12 and an electrifier 2 for preventing fogging prior to writing to an initial state and thereafter the residual magnetism is erased by a dejaussing head 3'. A magnetic image is then formed on the magnetic material layer of the body 1 by writing with a magnetic head 3 and is developed by the magnetic toner of the two-component type developer of a developing device 4 without direct contact of the developer layer with the body 1. The similar magnetic imag formation and the similar repetition by developing devices 5-7 are executed in the 2nd and succeeding rotation of the body 1 by which the stable and good multiple-images of multicolors, etc. are recorded without damaging the previously developed images.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multiple image recording method in which a plurality of toner images are superimposed on an image forming body by repeating the formation and development of a magnetic image on the image forming body. .

[Prior art]

As an image recording method in which toner images formed by multiple toners are superimposed, there is a method known as Japanese Patent Laid-Open No. 5
The methods described in Japanese Patent Application Laid-open No. 6-144452, Japanese Patent Application Laid-open Nos. 58-116553 and 58-116554 are known. In all of these methods, the image forming body has a photoconductive photoreceptor layer made of Se or the like on the surface, and development involves rubbing the electrostatic image with the same polarity at a low potential relative to the background potential. This is based on a reversal development method in which charged toner is attached. Generally, the electrostatic image forming performance of the photoconductive photoreceptor layer is relatively easily changed by the charging process.
Further, there are problems in that toner filming occurs and photoreceptor characteristics tend to deteriorate. Development using the reversal development method is a positive development method similar to that used in ordinary electrophotographic copying machines, that is, the electrostatic image potential is higher than the background potential.
Compared to development in which toner charged with opposite polarity is attached to the electrostatic image, toner adhesion control is difficult, and it is said that sufficient development density cannot be obtained and that it is easy to cause leakage in the recording device due to toner scattering. There is a problem.

On the other hand, as a method of forming a magnetic image on the magnetic layer using an image forming body having a magnetic layer on the surface, JP-A-50-90342, JP-A-51-100732, JP-A-51-100732, One disclosed in Japanese Patent No. 106253/1983 is known. This magnetic image recording method is excellent in that it can separate the ability to form an electrostatic image by corona discharge or the like applied to the photoreceptor and the ability to form a toner image. In other words, in the magnetic image recording method, the magnetic image is formed using the entire interior of the magnetic layer without undergoing changes in the surface condition as in the case of a photoconductor, while the toner image forming ability is dependent on the surface of the magnetic layer. considered to be shared.

Such a method has the feature that color information can be newly formed as a magnetic image independently of the toner image formed on the magnetic layer. However, the toner image formed on the magnetic layer has always been monochromatic.

[Purpose of the invention]

An object of the present invention was to solve the problems in the conventional multiple image recording method as described above, and to stabilize the formation of a magnetic image by using a means for forming a magnetic image on a magnetic layer. The object of the present invention is to provide a new color image and recording method by devising a method for superimposing development on a magnetic layer.

[Structure of the invention]

The above object has been achieved by a multiple image recording method characterized in that a plurality of toner images are superimposed and formed on the image forming body by repeating the formation of a magnetic image on the image forming body and the toner development. .

That is, in the present invention, a large number of magnetic recording heads are placed opposite to an image forming body composed of a magnetic layer and, if necessary, an insulating layer, and while the image forming body is moved at a constant speed, the image forming body is moved to each magnetic recording head. An image is written by forming a large number of magnetized regions in the magnetic layer of the image forming body by sending an image signal current synchronized with the magnetic layer, and then magnetic toner is deposited there and developed to obtain a toner image. By repeating image writing and development, a plurality of toner images are superimposed and formed on an image forming body to perform multiple image recording. Development is carried out under conditions where the developer layer formed in the developing device does not come into direct contact with the surface of the image forming body.In this way, the toner image once formed is free from damage during the next development, and multiple It is possible to superimpose toner images.

Furthermore, a color image can be recorded by using a plurality of toner images in combination with toners of different colors, such as yellow, cyan, magenta, and black toners.

Hereinafter, the present invention will be explained in detail with reference to illustrated examples.

FIGS. 1 and 2 are schematic configuration diagrams showing an example of a recording device used to carry out the method of the present invention, FIG. 3 is a partial sectional view of the recording device showing an example of a developing device, and FIGS. 6 each is a flowchart for implementing the method of the invention.

In Fig. 1, reference numeral 1 denotes a drum rotating in the direction of the arrow, provided with a magnetic layer formed on a metal substrate by vapor deposition, sputtering, or coating of a magnetic material dispersed in a binder, and an insulating layer. Upper image forming body, 2 is a pre-writing charger, 3' is a magnetic erasing head, 3 is a magnetic recording head, 4 to 7
8 is a developing device; 8 is a pre-transfer charging device; 9 is a transfer device for transferring a color image formed by overlapping color toner images formed on the image forming body 1 onto a recording medium P; 10 is a transfer device for transferring a color image; A fixing device for fixing the image on the recording medium P; 11 and 13 are static eliminators; 12 is a cleaning member 1 consisting of a fur brush, blade, etc. that operates in direct contact with the surface of the image forming body 1;
．． 2a is a cleaning device that comes into contact with the surface of the image forming body 1 after color image transfer to remove residual toner.

Note that one of the pre-writing charger 2 and the static eliminator 13 may be omitted. Or omit the static eliminator 11 and use the static eliminator 1.
It is preferable to use 3 as well. As the pre-writing charger 2, it is particularly preferable to use a scorotron corona discharger as shown in the figure. When a scorotron corona discharger is used, the image forming member 1 can be uniformly charged and neutralized without being affected by the previous charging state. Static eliminators 11 and 13
It is also preferable to use a scorotron corona discharger.

Furthermore, the pre-transfer charger 8 may be omitted if the transfer device 9 alone can perform sufficient transfer.

A magnetic image is formed on the magnetic layer of the image forming body 1 by recording heads 31-i, which are arranged in one or more rows. As the developing units 4 to 7, those having the structure shown in FIG. 3 are preferably used.

In FIG. 3, 31 is a developing sleeve made of a non-magnetic material such as aluminum or stainless steel, 32 is a magnet body provided inside the developing sleeve 31 and has a plurality of magnetic poles in the circumferential direction, and 33 is the developing sleeve 31. A layer thickness regulating blade regulates the thickness of the developer layer formed on the developer sleeve 31; a scraper blade 35 removes the developer layer after development from above the developing sleeve 31; a scraper blade 35 stirs the developer in the developer reservoir 36; Stirring rotary body, 37F'i toner hopper, blades supply toner from the toner hopper to the developer reservoir, a toner replenishment roller having a recess into which toner enters, 39 is connected to the developing sleeve 31 via a protective resistor of 4° as the case may be. A bias voltage having a vibration component is applied to the developing sleeve 3.
This is a power source for forming an electric field to control the movement of toner between the developing sleeve 3 and the image forming body 1.
1 and the magnet 32 rotate in the directions of the arrows, but even if the developing sleeve 31 is fixed, the magnet 32 is fixed, or the developing sleeve 31 and the magnet 32 may rotate in the same direction. When the magnet body 32 is fixed, usually in order to make the magnetic flux density of the magnetic pole facing the image forming body 1 smaller than the magnetic flux density of other magnetic poles, the magnetization is weakened or a magnetic pole of the same or different polarity is placed there. The two magnetic poles are sometimes placed close to each other in a sandwiched manner, instead of directly facing the developing area.

In such a developing device, the magnetic pole of the magnet body 32 in the developing area is magnetized to a magnetic flux density of usually 0 to 1500 Gauss, which is enough to not destroy the magnetic image, and the magnetic force causes a magnetic flux of M (851 fA) to be applied to the surface of the developing sleeve 31. 36 developer is adsorbed, and the thickness of the adsorbed developer is regulated by a layer thickness regulating blade to form a developer layer, and the developer layer is rotated 10 times in the same direction or opposite to the direction of the arrow. (the same direction in the figure), and the image forming body 1 is moved in the developing area where the surface of the developing sleeve 31 faces the surface of the image forming body l.
The remaining magnetic image is removed from the surface of the developing sleeve 31 by a scraper blade 34 and returned to the developer reservoir. The development temperature is
The temperature at which the color toner images are repeated (at least for the second and subsequent development steps) is to prevent the toner attached to the image forming member 1 from the previous development from being shifted during the subsequent development. It is particularly preferable to use non-contact jumping development conditions in an alternating current electric field.FIG. 3 shows development under non-contact jumping development conditions.

The method of the present invention can use either a so-called two-component developer consisting of a mixture of magnetic toner and a magnetic carrier, or a so-called one-component developer consisting only of magnetic toner, but it is necessary to add a large amount of magnetic material to the toner. It is preferable to use a two-component developer, which is free from toner particles and whose toner chargeability can be easily controlled. Magnetic materials generally exhibit a black to brown color, and if a large amount is added to a toner, the color becomes dark and unclear.

Magnetic carriers used in two-component developers (°C) include resins such as styrene thread resin, vinyl resins, ethyl resins, rosin-modified resins, acrylic resins, polyamide resins, epoxy textiles, and polyester resins, triiron tetroxide, γ-Fine particles of ferromagnetic or paramagnetic substances such as ferric oxide, chromium dioxide, manganese oxide, ferrite, manganese-copper thread alloy, etc. are contained, or the surface of the particles of these magnetic substances is made of resin coated with a resistivity of 1.
Preferably, the insulating carrier has a resistance of 0 AΩ or more, preferably about 10 13 ρ or more. If this resistivity is low, when a bias voltage is applied to the developing sleeve 31, a charge is injected into one carrier particle, making it easy for the carrier particles to adhere to one surface of the image forming body. The problem arises that no voltage is applied. In particular, if the carrier adheres to the image forming body 1, it will adversely affect the tone of the color image.

The resistivity was determined by placing the particles in a container with a cross-sectional area of o5ocrI and tamping them, then applying a load of 1000 V on the packed particles, and applying 1000 V between the electrode that also served as the load body and the bottom electrode. This value is obtained by reading the current value when applying a voltage that generates an electric field of /cm.

Furthermore, if the average particle size of the carrier is less than 5 μm, the magnetization will be too weak, and if it exceeds 50 μm, the image will not be improved, breakdown or discharge will easily occur, and high voltage will not be able to be applied. Diameter is 5μm or more 50μ
m or less, and if necessary, a suitable amount of a flow agent such as hydrophobic silica may be added as an additive.

The toner used in the method of the present invention is a magnetic toner in which a colorant and an appropriate amount of magnetic material are dispersed in a known resin commonly used for toners. Resins include phenol, polystyrene, alkyd, polyacrylic,
Polyethylene, B6 or polycarbonate, polyester, polyamide, BoI noether, polyolefin, polystyrene.

Styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-ethylinone-based unsaturated monoolefin copolymer, styrene-vinyl ester copolymer, styrene-vinyl ether copolymer, styrene-acrylonitrile copolymer, Synthesis of styrene-methacrylonitrile copolymer, styrene-acrylamide copolymer, styrene-vinylidene halide copolymer, polyvinyl acetate, copolymers of two or more of these, or mixtures of these polymers. Examples include resins.

Examples of the coloring agent include various inorganic pigments, organic pigments, direct dyes, acid dyes, basic dyes, mordants, acid mordant dyes, disperse dyes, and oil-soluble dyes.

Specific examples of this include carbon black as a black pigment;
Acetylene black, lamp black, graphite, mineral black, aniline black, cyanine black, etc.
Yellow pigments include yellow lead, zinc yellow, barium chromate, cadmium yellow, lead cyanamide, calcium leadate, naphthol yellow S1 Hansa Yellow 10G, Hansa Yellow 5G, Hansa Yellow 3G, Hansa Yellow 〇, and Hansa Yellow GR.

Hansa Yellow A, Hansa Yellow RN% Hansa Yellow R,
Pigment Yellow L, Benzine Yellow, Benzine Yellow G, Benzine Yellow GR, Permanent Yellow NCQ
, Palkan 7 Astro Yellow 5G.

Palkan 77 Stoe o-R, Tartrazine Lake, Quinoline Yellow Lake, Anthragen Yellow-60L.

Permanent Yellow FGL, Permanent Yellow H1
0G, Permanent Yellow) iR, Anthrapyrimidine Yellow, red pigments such as Red Red, Red Lead, Silver Vermilion, Cadmium Red, Permanent Red 4R, Rose Red, Polytan Dust Phosphoric Acid, Fire Red, Vermilion, Parachlororthonitroaniline Red , Lin Lufast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red F2R.

Permanent red F4R, permanent red FRL
, Permanent Red FRLL, Permanent Red F4RH, 7 Asto Scarlet VD, Palcan 7 Astorbin B, Eosin Lake, Rhodamine Lake, Rhodamine Lake Y1 Alizarin Lake, ThiA Indigo Lend B, Thio Indigo Maroon, Permanent Red F
GR, PV carmine dishes, etc. as blue pigments, ultramarine, navy blue, cobalt blue, alkaline flu lake, becoy
Examples include Cupru Lake, Victoria Blue Lake, Gold-free 47 Talocyanine Blue, Copper Phthalocyanine, Fast Sky Blue, Indanthrene Blue-R8, (Indanthrene Blue BS, Indigo, etc.), and yellow dyes such as C, 1, (Color Index) Direct Yellow 98% C, 1, Direct Yellow 89, C,
1, Direct Yellow 88 (more than direct dye), c, 1
．． Acid Yellow 1, C, 1, Acid Yellow 3,
C,1, Acid Yellow 7 (more acidic dyes), C,1
, Basic Yellow 1, C,1, Basic Yellow 2, C,1, Basic Yellow 11 (all basic dyes), C,1, Modern Toy Yellow-26 (mordant, acidic mordant dye), C,1, Disperse Yellow 1, C, 1, Disperse Yellow 3, C, 1, Disperse Yellow 4
(more than 1144 minutes), C, 1, V Rubent Yellow 2. Examples of red dyes include C, I, Direct Red 1.

Direct Red 2, C,1, Direct Red 4 (all direct dyes), C,1, Acidlet 8, C,I.

Acid Red 13, C,1, Acid Red 14 (all acidic dyes), C,1, Basic Red 2, C,1,
Basic red 14. c, t, basic red 2
7 (more than basic dye), C, 1, Modern Trend 21
(Mordant, Acid 1 Mordant Dye), C, 1, Disperse Red 1, C, I.

Dispersed thread 4. C, 1, Dispersed thread 5
(Disperse dye), C, 1, Solvent Red 1, C,
1, Solvent Red 3, C, 1, Solvent Red 8
(The above oil-soluble dyes), etc., as blue dyes, C, I.

Direct Blue 1, C, 1, Direct Blue 6, C
, L Direct Blue 22 (direct dye), C, I.

Acid Blue 1, C, 1, Acid Blue, C, I
.

Acid Blue 22 (more acidic dyes), C,1, Basic Blue 7, C,1, Basic Blue 9, C,1,
Basic Blue 19 (basic dye), C,1, Modern Blue 48 (mordant, acidic mordant dye), C,1, Disbirds Blue 1, C,1, Disbirds Blue 3,
C, 1, Disperse Blue 5 (disperse dye), C,
I.

Solvent blue 2. C, 1, Solvent Blue 11,
C, 1, Solvent Blue 12 (oil-soluble dyes), etc.
Examples include, but are not limited to. Furthermore, the color of the toner is not limited to the above four colors,
It can be freely selected depending on the purpose of use.

As the magnetic material that imparts magnetism to the toner, the same material as that used in the carrier can be used, and the amount added is preferably ω weight percent or less of the toner so as not to impair the color clarity of the toner. , 5 to weight percent is particularly preferred.

Furthermore, in order to improve the color clarity of the toner, a colored magnetic material or a transparent magnetic material using rare earth elements can also be used.

Suitable colored magnetic materials include iron oxide (base/gara) for red color, tooth surface coated with oxidized steel, and Nl.
There are some that have cadmium red adsorbed on them.

Furthermore, it goes without saying that various known additives commonly used in toners, such as a charge control agent, can be added to the magnetic toner.

Further, the toner used in the present invention has an average particle size of 1 to 20
μm is preferable, and the average charge amount is 1 to 300 μm.
.mu.c/g, lf4 IC: (-30 .mu.s/H is preferable. When the average particle diameter of the toner is less than 1 .mu.m, it becomes difficult to separate from the carrier, and when it exceeds 1 .mu.m, the resolution of the image decreases.

When a developer made of a mixture of insulating powder and magnetic toner as described above is used, the bias voltage applied to the developing sleeve 31 shown in FIG. Settings can be easily performed without fear of leaks.

The above is a description of the developing device and developer preferably used in the method of the present invention, but the present invention is not limited thereto.
The developing device and developer described in each of the publications No. 553 to 116554 may be used, and more preferably, the developing device and developer described in Japanese Patent Application Nos. 58-57446 and 58-96900 to 96903 previously filed by the applicant of the present application may be used. No. 58-97973
It is possible to perform non-contact jumping development using a two-component developer using the developing devices and developers described in each specification of the above-mentioned patent application.

Further, when developing with a one-component developer using only magnetic toner, U.S. Pat.
A developing device such as that described in Japanese Patent No. 893,418 can be used. A developing device having two or more magnetic rollers may also be used.

The electric bias including a vibration component applied during development must be set under conditions such that it does not disturb the toner image already formed on the image forming body or cause color mixing. Bias conditions such as those used in conventional non-contact jumping development, such as those disclosed in JP-A-55-18656 to JP-A-18659 and JP-A-56-106253, are caused by a strong alternating current electric field. The toner image that has already been formed may be damaged by the vibration of the toner. When repeating the development according to the present invention to overlap toner images, it is necessary to set the strength of the alternating current component of the bias within an appropriate range that allows the next toner image to be completely formed without damaging the existing toner image. It is.

When carrying out the method of the present invention, the bias condition is 0.2≦VAC/(d”f) ((vAc/a) −1500) / f≦1.
It is preferable that the formula satisfies the formula 0, and when a -component developer is used, it is preferable that the formula satisfies 0.2≦VAC/(d−f)≦1.6.

In the above equation, vAc is the amplitude (V) of the AC component of the developing bias (not the effective value), and f is the frequency (lIz
), di- is the gap G between the image forming member and the developer conveying member such as a sleeve.

Furthermore, since the order of colored toners when superimposing images affects the tone of the color image, it is necessary to select the most suitable order depending on the purpose.

Although the above description has been made using the recording apparatus shown in FIG. 1, the method of the present invention can also be carried out using a recording apparatus such as that shown in FIG. In FIG. 2, members having the same functions as those in FIG. 1 are designated by the same numbers as in FIG. 1.

The recording device shown in FIG. 2 is a recording device that uses a continuous recording body provided with a magnetic layer and a colorless insulating layer on the surface of a conductive substrate to form an image forming body 1'. Formation and development of a magnetic image are repeated while the image forming body 1' is linearly fed. That is, along the conveyance path of the image forming body 1', a pre-writing charging vj2, a magnetic erasing head 3', a magnetic recording head 3, and developing units 4 to 7 are repeatedly arranged in parallel at °C, and the final trap color image is formed. A fixing device 10 is provided to fix the image on the image forming body 1'. This recording device does not require a pre-transfer charger, a transfer device, a static eliminator, or a cleaning device, and can also record continuous color images. However, in order to prevent the image forming member 1' from sagging, the tension may be increased.

Although not shown, it is necessary to provide a support roller in the middle of the image forming body 1' so that the toner attached to the image forming body 1' is not offset.

Also in the recording apparatus as shown in FIG. 1, the image forming body 1 is placed on the drum at the second r! ! Image forming body 1 used in the recording device of J.
If the image forming body similar to ' is wound around, the pre-transfer charger 8, the transfer device 9, the static eliminator 11, and the cleaning device 12 will be unnecessary. Further, in order to hide the color of the magnetic layer, it is desirable to provide a conductive layer or an insulating layer having a white color or a desired color.

For carrying out the method of the invention, it is preferable to use an image-forming body having a highly insulating layer as the image-forming body. In general, once the developer adheres to the image forming body, it becomes extremely difficult to remove due to the mirror image force in addition to van der Waals force, causing problems such as fogging and a decrease in transfer rate. This can be prevented by providing the image forming member with an appropriate charge of the same sign as that of the toner. However, ordinary magnetic image forming bodies consisting of a conductive substrate and a magnetic layer have low insulation properties and are difficult to charge.However, charging can be achieved by providing an insulating layer on the surface of the magnetic body. . By using an image forming body with an insulating layer on the magnetic surface, unnecessary toner adhesion can be prevented and transfer efficiency can be increased, and a charger can be placed before writing the magnetic image to prevent charging. It is possible to prevent the occurrence of capri. The insulating layer is also effective for retaining the magnetic layer and preventing toner filming. Further, even if toner filming occurs, there is no problem in practical terms as long as it is on the insulating layer. If the magnetic layer is electrically conductive, it may also serve as the electrically conductive substrate. If the thickness of the insulating layer is too large, the density and magnetization of the recorded magnetic image will be reduced, so the thickness is preferably at most .mu.m, particularly at most 10 .mu.m.

FIG. 1 shows an example of a recording apparatus using an image forming body having an insulating layer as described above. When an image forming body without an insulating layer is used, the pre-writing charger 2 and the static eliminator 13 are Not necessary.

In the example shown in FIG. 1, the magnetic image is recorded by a parallel magnetization recording method using a ring head, but a perpendicular magnetization method can be used as well as a parallel magnetization method as a means of magnetization writing. In this case, it is preferable to fix the magnet body 32 and make the magnetization direction different from the direction of magnetization caused by the polarization of the opposed magnetic poles, so that the toner is difficult to spread to the non-image area and the toner is easy to spread to the image area. At this time, it goes without saying that the magnetization method and the easy magnetization direction of the magnetic layer should be matched.

Further, the magnetic erasing head 3' and the magnetic recording head 3 can be installed in front of the pre-writing charger, at the front and rear, or at the back as shown in FIGS. 1 and 2.

Hereinafter, an image recording process according to the method of the present invention using the recording apparatus as described above will be explained with reference to FIGS. 4 to 6.

In the example shown in FIG. 4, in the recording apparatus shown in FIG. 1, the surface of the image forming body 10 is first neutralized by the static eliminator 11, cleaned by the cleaning device 12 (1), and then charged by the pre-writing charger 2 to prevent fogging. The initial state (2) is that the toner is charged to an appropriate potential e having the same sign as the toner (the dotted line indicates the presence of charge).

Next, after the residual magnetism m is demagnetized by the degaussing head 3' (3), the recording head 3 performs the first writing on the surface to form a magnetic image M, 4).

is developed for the first time in the developing device 4 to obtain the first image T1 (5
) Then, in the recording apparatus shown in FIG. 1, the image forming body 1 enters the second rotation, and demagnetization is performed by the erasing head 3' (6).
, a second writing is performed by the recording head 3 (7), and the magnetic image M thus formed is developed a second time by the developing device 5 to obtain a second image T (81 degrees and below similarly). Demagnetization writing and development are repeated for the third and fourth times, and as a result, a color image in which color toner images are superimposed is formed on the image forming member L, and the color image is transferred to the first
In the recording apparatus shown in the figure, after being easily transferred by the pre-transfer charger 8 and transferred to the recording medium P by the transfer device 9,
The image is fixed on the recording medium P by the fixing device 10, and in the recording apparatus shown in FIG. 2, it is directly fixed on the image forming body 1' by the fixing device 10. In the recording device fσ shown in FIG.
One cycle of color image recording is completed by removing residual toner in a cleaning device 12 and, if necessary, removing static electricity in a device 13. Even when the recording apparatus shown in FIG. 2 is used, the image forming process is the same except that the form of the image forming body 1' is different.

Figure 5 shows a simplified process by omitting uniform charging from the process in Figure 4, and Figure 6 is different from Figure 4 in that the charger 2 is operated before each write to make the charging uniform. Although different processes are shown, their basic operation is the same.

Note that 'r and J'r in FIGS. 4 to 6 are toners of different colors deposited on the one-image forming body 1 or 1'.

In the method of the present invention, development is performed under the five non-contact jumping development conditions described above, so that the developer layer is not removed from the development sleeve 31 in the developing devices other than those used for each development. Also, connect the developing sleeve 31 to the power supply 3.
The developing sleeve 31 can be easily kept in an inactive state by disconnecting it from the developing sleeve 31 and placing it in a floating state, or by grounding it, or by actively applying a DC bias voltage of the opposite polarity to the charging of the toner to the developing sleeve 31. Among these, it is preferable to maintain the developing device in an inoperative state by applying a bias voltage having a polarity opposite to that of the toner.

Next, Figures 4 to 6 were recorded using the recording device shown in Figure 1.
The illustrated examples will be described more specifically as Examples 1 to 3, respectively.

Example 1 A recording apparatus as shown in FIG. 1 was used. Image forming body 1 is a Co alloy coated with a thickness of 10 μm on an Al substrate by electron beam heating.
, and an insulating layer of 5 μm was provided on its surface, and its circumferential speed was 180 questions/sec.

The surface of this image forming body 1 is charged to +50V by a pre-writing charger 2 using a scorotron corona discharger, and then demagnetized by a magnetic eraser whose tip is approximately 30 βm away from the surface of the image forming body 1. Next, the first image writing was performed using the recording head 3, which was similarly separated, at a distribution density of 10 spots/home. As a result, a first magnetic image was formed on the image forming body 1. This magnetic image is shown in Fig. 1.
il, the first development was carried out using developer unit 5. The developing device 5 contains a carrier containing magnetite dispersed in a weight percent of resin with an average particle size of I μm, magnetization of 30 emu/g, and resistivity of 1014 Ωα or more, and a styrene-acrylic/I/m resin. A developer consisting of 5 parts by weight of magnetite, 10 parts by weight of copper phthalocyanine as a cyan pigment, and a positive magnetic toner having an average particle size of 10 μm, with the addition of other charge control agents, was prepared under conditions such that the ratio of toner to carrier was 10% by weight. Using. The outer diameter of the developing sleeve 31 is 30 mm, the rotation speed is 100 rpm, and the N of the magnet body 32 is 100 rpm.
, the magnetic flux density of the S magnetic pole i! 500 gauss, rotation speed is 11
Thickness of the developer layer in the developing area is 0.7 m. The gap between the developing sleeve 31 and the image forming body 1 is 0.8 m. The DC voltage component of the developing sleeve 31 is 150 V and 1.5 KHz.
A non-contact jumping development condition was used in which a bias voltage consisting of an AC voltage component of 0 OV was applied. In the examples below, the alternating current component is a sine wave and the values shown are effective values.

The same magnetic erasing head 3 is used again without operating the pre-transfer charger 8, the static eliminators 11 and 13, the cleaning device 12, and the pre-writing charger 2 on the surface of the image forming body 1 that has been subjected to the first development. ', and a second write was performed using the recording head 3 with the spot position shifted from the first write with the same spot density. Next, a second development is performed using a developer toner containing polytungstophosphoric acid as a magenta pigment instead of a cyan pigment, and using a developer 5 under the same conditions as the developer 4 except for the cyan pigment. went. Similarly, degaussing, third writing, and third development using developer 6 under the same conditions as developer 4 except that yellow pigment was added to the developer toner and toner containing a benzidine derivative was used. Developing unit 4 was used except for demagnetization and fourth writing, and the use of toner to which carbon black was added as a black pigment.
A fourth development was performed using developer 7 under the same conditions as described above. The color image thus formed on the image forming body 1 was transferred and fixed onto the recording body P as described with reference to FIG. Further, the surface of the image forming body 1 to which the color image was transferred was neutralized by a static eliminator 11, and residual toner was removed by a cleaning device 12.

The recorded image obtained in the above manner was a very clear color image with little color mixing of color toners.

In this embodiment, the spot position of the subsequent writing may be made to overlap the spot position of the previous writing and the spot position, and the recording head may be adjusted so as to adjust the development density of each color during writing and development. Voltage value of the DC component or AC component of the recording current or voltage applied to the developing sleeve in step 3,
The selection time of frequency and time selection may be changed. If the writing spot positions are overlapped, color mixing occurs and the colors tend to become muddy, but this can be done without reducing the resolution. In this case, the order of colors to be developed is particularly important. Further, by adjusting the development density of each color as described above, a color image with a changed tone can be obtained.

Example 2 The same recording device as in Example 1 was used, and after the static electricity was removed and demagnetized by the static eliminator 11, charging by the pre-loading charger 2 before the first writing in Example 1 was not performed, and the first writing was performed using the same recording device as in Example 1. A magnetic image was formed with respect to the background potential OVK, and during development, a DC voltage of -50V and 3Ktz) was applied to the developing sleeve 31.
A superimposed voltage of 000 V AC voltage is applied as a bias voltage, static electricity is removed and demagnetized by the static eliminator 11 before the second and subsequent writing, and the background potential Ov is also lowered by ℃ during the second and subsequent writing. Color image recording was carried out under the same conditions as in Example 1, except that a magnetic image was formed on the sample.

The recorded image obtained was a color image with excellent clarity, similar to that in Example 1.

Example 3 Using the same recording device as in Example 1, the cylinder was charged to +300V by the charger 2VC before the first write, and after degaussing, the cylinder was written once to form a magnetic image against a background potential of +300.
During development, a superimposed voltage of +3oov DC voltage and 2 KHz, IKV AC voltage was applied as a bias to the developing sleeve 31, and a pre-writing charger 2 was used before degaussing and the second and subsequent writing. Color image recording was performed under the same conditions as in Example 1 except for the above. The recorded image obtained was a color image with poor clarity, similar to that in Example 1.

〔Effect of the invention〕

According to the present invention, by using an image forming means that separates the image forming ability and the toner image forming ability, it is possible to easily change the tone etc. of a color image, and to create a high tone image with excellent clarity. Excellent effects such as being able to record a single color image and stable recording can be obtained.

The present invention can also be applied to -C when the image forming body is in the form of a belt or sheet, or when the image forming body is mounted on a substrate using electrofax paper, and It may also be one that fixes the formed color image using toner without transferring it. In that case, although it is necessary to consider the order in which the color toner images are superimposed, a transfer device, a cleaning device, etc. are not required. Of course, the static eliminator can also be omitted when the toner has a specific polarity and charge amount and is transferred. Also, in addition to corona transfer, is there bias roller transfer or adhesive transfer? Direct pressure transfer or transfer via an intermediate transfer member may be used, and fixing is not limited to heat roller fixing.

Furthermore, in the embodiments of the present invention, a magnetic recording head is used as a writing means to transfer a magnetic image onto the magnetic layer.
Other means can be similarly used as long as they are formed. In other words, a method in which a demagnetized magnetic layer is not passed through a uniform magnetic field, but is heated imagewise by a heating means such as a laser, and then cooled in a magnetic field to form a magnetic image ((
It is also a force box iJ function that applies.

Furthermore, although the above embodiments have been described only regarding the recording of color images, the method of the present invention can also be applied to superimposition of images of the same color. m1ll
:ge? A! i'7'/it hel f%? ! 'rz
W<aLmasr(414b) It is also possible to record in combination.

[Brief explanation of the drawing]

1 and 2 are schematic configuration diagrams showing an example of a recording device used to carry out the method of the present invention, FIG. 3 is a partial sectional view of the recording device showing an example of a developing device, and FIGS. FIG. 6 is a flowchart of the implementation of the method of the invention, respectively. 1.1'... Image forming body, 2... Pre-writing charger, 3
... Recording head, 4-7... Developing device, 8... Pre-transfer charger, 9... Transfer device, 10... Fixing device, 11
... Static eliminator, 12... Cleaning device, 31... Developing sleeve, 32... Magnet, 33...
・Layer thickness regulation blade, ah...scraper blade, ah...stirring magnet, ah...developer reservoir, 37...
・Toner hopper, Seki... Toner supply roller, 39・
...Power supply, 4o...Protection resistor. Agent: Patent Attorney No FE Kanchika

Claims (1)

[Scope of Claims] (1) Multiple image recording characterized in that a plurality of toner images are superimposed and formed on the image forming body by repeating the formation of a magnetic image on the image forming body and the toner development. Method. (2) The multiple image recording method according to claim 1, wherein a plurality of toner images on the image forming body are formed using toners of different colors. (3) The multiple image recording method according to claim 1 or 2, wherein the image forming body comprises at least a magnetic layer and a surface insulating layer. A multiple image recording method according to claims 1 to 3. (5) The multiple image recording method according to any one of claims 1 to 4, wherein the developer used to form the toner image is a two-component developer mainly consisting of a magnetic toner and an insulating carrier. (6) The multiple image recording method according to any one of claims 1 to 5, wherein the formation of the magnetic image is repeated by the same magnetic recording head. (7) Prior to the formation of the magnetic image, the image recording method A multiple image recording method according to any of claims 1 to 6, in which the entire surface of the image forming body is demagnetized. The multiple image recording method according to items 1 to 7. (9) After transferring the plurality of toner images formed on the image forming body to a transfer machine, cleaning the surface of the image forming body by a cleaning means. A multiple image recording method according to claims 1 to 8.