JPH08286473A - Recording method and device - Google Patents

Abstract

PURPOSE: To repeatedly obtain a large number of high image quality prints by a single time of latent image formation even if a latent image is not formed every time the development and transfer are repeated by electrifying a ferroelectric latent image recording medium before the development. CONSTITUTION: This recording device is constituted to include a latent image forming means 2 for forming the latent image based on printing information on the ferroelectric latent image recording medium, a developing means 4 developing the latent image, to obtain a visible image and a transfer means 5 transferring the visible image onto a recording medium and provide an electrifying means 3 before the developing means 4. Preferably, a charge is uniformly imparted to the latent image recording medium by the electrifying means 3 and preferably, a destaticization means 8 is provided after the transfer means 5 and just before the electrifying means 3. Further, it is preferable that the charge having a polarity opposite to that of the electrifying means 3 is uniformly imparted to the latent image recording medium by the destaticization means 8. In this way, when the charge is uniformly applied to the full surface of the ferroelectric latent image recording medium on which the latent image is formed, the development so as to amplify the surface potential difference between an image part and a background part is attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording method and apparatus used in a printer, a copying machine or the like by an electrophotographic process.

[0002]

2. Description of the Related Art In an electrophotographic process, it is known to use a recording body having a ferroelectric latent image recording medium in place of a widely used photosensitive body. The electrophotographic process using such a latent image recording medium utilizes internal polarization of the latent image recording medium to form a latent image, and is superior in persistence of latent image holding as compared with the electrophotographic process using a photoconductor. Therefore, it is considered to be a process suitable for so-called retention copy, in which the same printed matter is repeatedly obtained from one latent image. Then, the latent image formed on the latent image forming medium is developed by toner particles as in the electrophotographic process using a photoconductor, and the obtained toner image is transferred and fixed on a recording medium such as paper. .

By the way, in the electrophotographic process, an electrostatic force is applied to the toner particles during development and transfer, and this electrostatic force tends to deteriorate the latent image on the latent image forming medium. Therefore, when the same printed matter is repeatedly obtained from one latent image, deterioration of the latent image formed on the latent image forming medium due to this electrostatic force is suppressed, and the image portion (area where toner particles adhere) of the latent image and the background are suppressed. It is extremely important to maintain a constant surface potential difference from a portion (a region where toner particles are not attached) in order to maintain the image quality of a printed matter.

Regarding such image quality maintenance, Japanese Patent Laid-Open No.
JP-A-255880 proposes application of the pyroelectric effect to development. The invention disclosed in this publication intends to increase the surface potential difference by increasing the temperature of the ferroelectric recording medium at the time of development, suppress the deterioration of the latent image and improve the developing speed and the fogging of the background portion. To do. However, the surface potential difference generated by the pyroelectric effect is not so large, and the repeated heating-cooling rather deteriorates the latent image, and when a plurality of print copies are obtained by one latent image formation, high image quality is obtained. There was a problem that the printing of could not be maintained.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art, and to perform development and transfer in an electrophotographic process using a recording medium having a ferroelectric latent image recording medium. It is an object of the present invention to provide a recording method and apparatus useful for obtaining a large number of high-quality printed matter repeatedly by forming a latent image without forming a latent image each time it is repeated.

[0006]

In order to achieve the above object, the inventors of the present invention have made diligent studies on ferroelectric latent image recording media based on the knowledge gained through many years of experience, and conducted various experiments. Tried. As a result, when a uniform charge is applied to the entire surface of the ferroelectric latent image recording medium on which the latent image is formed, the phenomenon that the surface potential difference between the image portion and the background portion is amplified is found, and the present invention is realized. It came to eggplant.

That is, according to the recording method of the present invention, a latent image forming step of forming a latent image based on print information on a ferroelectric latent image recording medium, and developing the latent image into a visible image. The constitution includes a developing step and a transfer step of transferring the visible image onto a recording medium, and has a charging step before the developing step. Preferably, in the charging step, electric charges are uniformly applied to the latent image recording medium.

Further, preferably, a static elimination step is provided after the transfer step and before the subsequent subsequent charging step. More preferably, in the charge eliminating step, charges having a polarity opposite to that of the charge step are uniformly applied to the latent image recording medium. on the other hand,
According to the recording apparatus of the present invention, a recording body having a ferroelectric latent image recording medium, latent image forming means for forming a latent image based on print information on the latent image recording medium, and developing the latent image. The developing means includes a developing means for converting the visible image into a visible image and a transferring means for transferring the visible image onto a recording medium, and a charging means is provided between the transferring means and the developing means.

Preferably, the charging means is a corotron type charger. Further, preferably, a charge removing unit is provided between the transfer unit and the charging unit. More preferably, the static eliminating means is a charger. Preferably, the static eliminating means is a corotron type charger. Further, preferably, the latent image recording medium is a ferroelectric ceramic.

More preferably, the latent image recording medium is a ferroelectric polymer.

[0011]

Further, the present invention will be described in detail. In a recording apparatus for executing the recording method, a recording body having a ferroelectric latent image recording medium is used. The recording body has a conductive support and a latent image recording medium made of ferroelectric ceramics or polymer formed on the support, and has a drum or belt shape.

The support is preferably one having conductivity, and a material such as an aluminum alloy or a nickel alloy is suitable. However, even if it is a synthetic resin film having no conductivity, for example, a polyester film, a conductive layer made of aluminum, copper, nickel, silver, chromium or the like is formed by a vapor deposition method, a sputtering method, or the like, or It may be a conductive elastic material such as fluororubber in which carbon black is dispersed.

The latent image recording medium formed on the support is made of a ferroelectric material such as ferroelectric ceramics, ferroelectric polymer, ferroelectric ceramic particles or a mixture of powder and resin binder. These ferroelectric materials are
Hysteresis characteristics are shown in relation to (electrical displacement) -E (electric field). Here, the remanent polarization (absolute value of D when E = 0) in these ferroelectric materials is a factor that determines the adhesion amount of toner particles during development. Therefore, in view of the amount of charge per unit weight of general toner particles, in order to secure a sufficient printing density, the ferroelectric material should have a remanent polarization of 0.01 μC / cm ² or more. preferable.

Ferroelectric ceramics include barium titanate (BaTiO ₃ ), zircon and lead titanate (Pb).
(Ti, Zr) O ₃ ), lead titanate (PbTiO ₃ ), lead niobate (PbNb ₂ O ₆ ) and the like can be used. The ferroelectric latent image recording medium made of these materials can be formed on the support by a known thin film forming method such as a sol-gel method, a sputtering method, a CVD method (chemical vapor deposition method). Ferroelectric ceramics are resistant to mechanical abrasion and can improve printing durability of a latent image recording medium.

As the ferroelectric polymer, polyvinylidene fluoride (PVDF), vinylidene fluoride / ethylene trifluoride copolymer P (VDF / TrFE), vinylidene fluoride / tetrafluoroethylene copolymer is used. P (VDF / T
eFE), vinylidene cyanide / vinyl acetate copolymer P
(VDCN / VA), vinyl fluoride / trifluoroethylene copolymer P (VF / TrFE), vinyl fluoride / trifluoroethylene copolymer P (VF / TrFE) as vinylidene fluoride as a third component, A copolymer obtained by adding tetrafluoroethylene, hexafluoroacetone, hexafluoropropylene, or the like, an amide polymer such as nylon 7 or nylon 11, and the like can be used. The latent image recording medium made of these materials can be formed by a well-known melt solidification method, casting method, dipping method, spin coating method, or spray method. It can also be formed by adhering these thin films on a support. It is preferable to use such a stretched film because the PVDF film exhibits a strong dielectric property when it is uniaxially or biaxially stretched. P (VDF / T
rFE) and P (VDF / TeFE) can be easily formed into a ferroelectric thin film without stretching by a melt solidification method, a cast method, or a spin coating method, so that the degree of freedom in the construction of the latent image recording medium is increased. To do.

The ferroelectric latent image recording medium also includes the above-mentioned ferroelectric ceramics, preferably having an average particle size of 1 to 2.
It may be formed by coating a support with a mixture of 0 μm fine particles and a resin binder, for example, a copolymer resin of vinyl chloride and vinyl acetate, or the above-mentioned ferroelectric polymer. The thickness of the ferroelectric latent image recording medium is related to the effective applied voltage in the polarization step in the latent image forming step described later, and it becomes necessary to increase the voltage as it becomes thicker. Since the surface potential contrast value is determined by the thickness, the lower limit value of the thickness is also determined, and more preferably 1 to 50 μm.

Further, in the latent image recording medium, a thin overcoat layer is previously formed on the outermost surface with a silicone resin or a fluororesin so that the surface is not roughened when heated to a temperature higher than the melting point during latent image formation. Is preferred. As a forming method, a spray method, a spin coating method, a dipping method, or the like can be used. Here, the surface area of the latent image recording medium determines the page size of the printed matter to be obtained. Therefore, the surface area of the latent image recording medium is set to be larger than at least the page size of the printed matter to be obtained.

By the way, the recording apparatus of the present invention using such a recording medium, through the steps described below, repeatedly forms a large number of high quality printed matter by forming only one latent image. Latent image forming step: In this step, after the ferroelectric latent image recording medium is initialized, a latent image based on print information is formed on the latent image recording medium. There are several ways to do this:

First, first, a latent image recording medium is heated to a temperature above the Curie temperature of the ferroelectric material forming the latent image recording medium by using a heating device such as an infrared heater to initialize the latent image recording medium. After that, a local high electric field generator such as a multi-stylus is applied to the latent image recording medium, and an electric field higher than the coercive electric field (threshold electric field at which polarization reversal occurs) of the ferroelectric material is applied to form a latent image based on the print information. Form.

Secondly, a uniform high electric field generator such as a corona charger or a roller charger is applied to the latent image recording medium to apply an electric field higher than the coercive electric field of the ferroelectric material to achieve uniform polarization. Form a state. That is, it is initialized. Then, using a local high electric field generator, a latent image is formed on the latent image recording medium by applying an electric field having a polarity opposite to that of the above electric field, which is based on the print information, and which is higher than the coercive electric field of the ferroelectric material. .

Third, a uniform high electric field generator is used to apply an electric field higher than the coercive electric field of the ferroelectric material to the latent image recording medium to form a uniform polarized state for initialization. After a while
A latent image is formed by heating the ferroelectric material to a Curie temperature or higher based on print information using a local heating device such as a thermal head or a laser beam. When a heating means using light such as laser light is used, it is preferable to laminate a light absorbing layer on the latent image recording medium or to add a light absorbing agent such as a dye to the latent image recording medium because the heating efficiency is improved. .

Fourth, a uniform high electric field generator is used to apply an electric field higher than the coercive electric field of the ferroelectric material to the latent image recording medium to form a uniform polarized state for initialization. After a while
An electric field having a polarity opposite to that at the time of initialization, which does not cause polarization reversal at room temperature, and has an electric field which causes reverse polarization at a temperature reached by the ferroelectric material by a local heating device described later. A latent image is formed by heating the ferroelectric material below the Curie temperature based on the print information using a local heating device such as light. In this case, the ferroelectric material is preferably a material whose coercive electric field greatly changes with temperature.

Fifth, there is also a method of laminating a photosensitive material on a latent image recording medium and using it. In this method, the laminate is uniformly exposed and a uniform high electric field is applied by using a uniform high electric field generator to make the photosensitive material conductive so that the latent image recording medium is uniformly polarized. Is formed and initialized. Then, the photosensitive material is irradiated with light based on print information using a semiconductor laser or the like to make the irradiated portion conductive, and an electric field having a polarity opposite to that at the time of initialization is applied to polarize the irradiated portion. Invert to form a latent image.

The latent image formed on the latent image recording medium by the various methods described above is caused by the internal polarization (dipole) of the ferroelectric material. That is, the internal polarization of both the background portion and the image portion is perpendicular to the surface of the latent image recording medium, and the background portion and the image portion are
A so-called inverted polarization latent image in which the polarities of the surface are reversed, or the direction of internal polarization in one of the background portion and the image portion is perpendicular to the surface of the latent image recording medium (polarized state), and in the other area. Direction of internal polarization is random (unpolarized state)
Which is a so-called partially polarized latent image.

The high electric field generator used for initializing the latent image recording medium can also serve as a corona charger in the charging step described later. Charging step: In this step, electric charges are uniformly applied to the entire surface of the latent image recording medium on which the latent image is formed, and the surface potential difference between the image portion and the background portion is amplified. That is, in a latent image recording medium on which a latent image is formed, the surface potential generated varies depending on the state of internal polarization even if charges are uniformly applied to the entire surface. Although the mechanism of this phenomenon has not been completely clarified, D shown in FIG.
It can be inferred from the −E curve as follows. In FIG. 2, the horizontal axis represents the electric field (E: mC / m ² ), the vertical axis represents the electric displacement (D: MV / m), the vertical axis intercept Pr is the remanent polarization, and the horizontal axis intercept Ec is the coercive electric field. Indicates.

For example, in the case of a polarization inversion latent image, when the electric field E is E = 0 in FIG.
It is located at point B and point B (or vice versa).
In this state, an equal amount of charge (Δ
If Q) is given, the electric charge (ΔQ) corresponds to electric displacement. Therefore, by applying the electric charge (ΔQ), the image portion and the background portion move to the points AS and BS in FIG. At this time, if the electric field values at the points A S and B S are respectively a and b, the product of the difference in electric field value (ab) and the thickness d of the latent image recording medium, d × (ab) is the surface potential difference. It is thought that it will occur.

Therefore, in the latent image recording medium, the contrast of the surface potential is amplified between the image portion and the background portion,
It is possible to obtain a printed matter with high image quality such as an increase in print density and suppression of white background stains. In addition, this phenomenon is due to the charge (Δ
Q) is neutralized. Therefore, the image part and the background part are
Return from points and BS to the original points A and B. Therefore, by repeating this, a plurality of printed matter with uniform quality can be obtained by one latent image formation.

Here, for the purpose of uniformly applying electric charges, the corotron type charging device is preferable to the scotron type having a grid. Developing step: In this step, the toner particles are electrostatically adsorbed on the latent image recording medium to form the latent image into a toner image, that is, a visible image.

The development here may be so-called positive development using toner particles charged in the opposite polarity to the image area polarity, or so-called reversal development using toner particles charged in the same polarity as the background area polarity. Good. In any of the developments, by setting the development bias between the surface potential of the image portion and the surface potential of the background portion generated in the charging step, proper development can be performed while suppressing the white background stain with less fog in the background portion. . The developer containing toner particles may be a dry type or a wet type, and may be a one-component system or a two-component system. As a developing method, a well-known method such as a cascade developing method, a magnetic brush developing method, or an electrophoresis method can be used. Transfer step: This step is a step of transferring the toner image on the latent image recording medium developed in the developing step onto a recording medium such as paper or film. This transfer is a corona transfer method,
A well-known method such as a bias roll transfer method, a pressure transfer method, or an adhesive transfer method can be used.

It should be noted that instead of directly transferring the toner image from the latent image recording medium to the recording medium, it is also possible to first transfer the toner image from the latent image recording medium to the intermediate transfer medium and then to the recording medium. Fixing step: This step is a step of fixing the toner image transferred onto the recording medium in the transfer step onto the recording medium. This fixing can be performed by a known method such as a heat fixing method using a hot roll, a flash lamp, an infrared lamp or the like, or a pressure fixing method using a pressure roll. Cleaning step: This step is a step of removing, from the latent image recording medium, the toner particles that have not been transferred to the recording medium and remain on the latent image recording medium after the transfer step. This process is a brush cleaning method, a blade cleaning method,
It can be carried out by a known method such as a web cleaning method or an air blow cleaning method.

Printing is performed through the above steps, but in the case of so-called retention copy in which a large number of identical printed matter is obtained from one latent image, the latent image is held on the latent image recording medium in the second and subsequent printing. ing. Therefore, the latent image recording medium is
After the cleaning step, the procedure may be returned to the charging step and the steps such as development and transfer may be repeated. Therefore, in the following description,
A series of processing steps of repeating charging, development, transfer, fixing, and cleaning is defined as printing processing.

The above charging step may be carried out as necessary only when the contrast of the surface potential on the latent image recording medium on which the latent image is formed is lowered. In addition, in the case of retention copy, the exact same image is printed, so the cleaning step may be omitted. Further, when another image is printed, the printing process may be performed after returning to the latent image forming step.

In the printing process, after the transfer step, and
It is also effective to add a charge eliminating step before the charging step in the subsequent printing process. Static elimination step: This step is a step that enables higher-speed printing processing by forcibly neutralizing the charge (ΔQ) applied to the latent image recording medium in the charging step. That is, after the transfer step, a charge eliminating step is provided before the charging step in the subsequent printing process, and the charge of the opposite polarity, which is almost equal to that in the charging step, is uniformly applied to the latent image recording medium. In 2,
The image part and the background part are forcibly returned from points A S and B S to points A and B. As a result, the image portion and the background portion after the charging process can be repeatedly moved to the AS point and the BS point even if the time for one cycle in the printing process is shortened. By providing this static elimination step, even if the time for one cycle in the printing process is shortened, the image portion and the background portion of the latent image recording medium are
The transitions are A → AS → A and B → BS → B, respectively, and the same locus is drawn for each cycle. Therefore, the latent image recording medium can maintain a constant surface potential, and high-speed printing can be realized. Here, it is also effective to superimpose an alternating electric field on the latent image recording medium in order to enhance the charge removal effect.

[0034]

EXAMPLE As shown in FIG. 1, a recording apparatus comprises a recording body 1,
The electrophotographic printer includes a latent image forming unit 2, a charging unit 3, a developing unit 4, a transfer unit 5, a fixing unit 6, a cleaning unit 7, and a charge eliminating unit 8. The recording body 1 is, for example,
An aluminum drum coated with a 10 μm-thick ferroelectric latent image recording medium made of vinylidene fluoride / ethylene trifluoride copolymer P (VDF: TrFE = 66: 34) is rotated in the direction of the arrow. The recording body 1 includes a rotation speed switching unit (not shown), and the rotation speed can be switched in each of the latent image forming process and the printing process. Therefore, the recording body 1 can form a very high-definition latent image on the latent image recording medium by lowering the rotation speed in the latent image forming step as compared with each step of the printing process, for example. is there. Further, the aluminum drum of the recording body 1 has a potential holding means (for example,
Grounded) is connected.

The latent image forming means 2 is a multi-stylus head in which minute electrodes are arranged in an array, and forms a latent image on a latent image recording medium according to print information. The latent image forming means 2 is
A very high electric field can be locally applied to the latent image recording medium of the recording body 1. The latent image forming means 2 applies a high electric field having a polarity opposite to that of the charging means 3 to the latent image recording medium, which is higher than the coercive electric field, to the recording body 1 whose entire surface is uniformly polarized by the charging means 3 described later. , By generating local reversal polarization,
A polarization inversion latent image is formed. Here, the latent image forming means 2 is
Recording medium 1 only during a latent image forming step of forming a latent image on recording medium 1.
In the printing process, the print job is saved at a position away from the recording body 1.

The charging means 3 is an existing corona charger that uniformly charges the surface of the recording body 1. The charging unit 3 can be utilized as an initializing unit in the latent image forming process and an amplifying unit that amplifies the surface potential contrast of the latent image in the printing process. The developing means 4 is of a known roll developing system and has a developing solution tank 4a and a developing roll 4b. The developing solution is a wet type developer containing toner particles and a dispersion, and is accompanied by the developing roller 4b as it rotates, and comes into contact with the latent image recording medium of the recording medium 1. As a result, the latent image is developed with the toner particles and becomes the toner image 9. Here, the developing roll 4b is connected to a developing bias applying means (not shown), and adjusts the surface potential of the latent image after the charging process, that is, the potential between the surface potential of the image portion and the surface potential of the background portion. To be done.

The transfer means 5 is a known transfer means having a transfer roll 5a and a bias power source 5b which are arranged to face the recording medium 1, and the toner image 9 on the latent image recording medium is transferred to the transfer roll 5a and the recording medium. It is transferred to the recording paper 10 carried in between the recording paper 10 and the recording paper 10. The bias power source 5b generates a transfer electric field between the transfer roll 5a and the recording body 1. The fixing unit 6 is a well-known heat fixing unit including a heating roll 6a and a pressure roll 6b, and fuses toner particles on the recording paper 10 to fix the toner image 9 on the recording paper 10.

The cleaning means 7 is a sponge roll 7
The existing cleaning means including a and a blade 7b made of rubber removes the toner particles remaining on the recording body 1 in contact with the recording body 1. Here, the cleaning means 7
Can be brought into and out of contact with the recording body 1 because it can be brought into contact with the recording medium 1 as necessary when rewriting the latent image.

The charge eliminating means 8 uniformly applies a charge having a polarity opposite to that of the charging means 3 to the latent image recording medium, and the surface potentials of the image portion and the background portion of the latent image recording medium before development are respectively changed. The applied voltage is adjusted according to the voltage applied by the charging means 3 so as to keep the voltage substantially constant. That is, the static elimination means 8 is
The surface potential of the portion where the polarization is inverted by the latent image forming means 2 is adjusted so that the electric field applied to the latent image recording medium after the charging by the charging means 3 can be suppressed below the coercive electric field in the range where polarization inversion does not occur again. To do.

In the recording apparatus constructed as described above, a large number of high quality printed matter is repeatedly produced only by forming a latent image as follows. First, the cleaning means 7 is retracted to a position away from the recording body 1, and the charging means 3
The latent image recording medium of the recording body 1 is initialized with. At this time, the latent image forming means 2 is retracted to a position away from the recording body 1.

Then, the latent image forming means 2 is brought into contact with the recording medium 1, a high electric field having a polarity opposite to that of the charging means 3 is locally applied to the latent image recording medium based on the print information, and the latent image forming means 2 is applied in accordance with the print information. Form a polarization inversion latent image. Here, the latent image forming means 2 is
After the formation of the latent image is completed, it is evacuated to a position away from the recording body 1. Next, the entire surface of the latent image recording medium of the recording body 1 on which the latent image is formed is uniformly charged by the charging means 3 to increase the contrast of the surface potential between the image portion and the background portion. At this time, for example, when the voltage applied to the charging means 3 is −5 KV, the surface potential difference between the image portion and the background portion in front of the charging means 3 is 50.
V was less than V, while 200 to 1, after charging means 3
It was possible to amplify up to 000V.

Next, the developing means 4 electrostatically attracts the toner particles to the latent image to develop the latent image into a toner image 9.
After that, the toner image 9 on the developed latent image recording medium is
Transfer is performed on the recording paper 10 conveyed between the recording body 1 and the transfer roll 5a while applying a bias voltage by the transfer roll 5a.

Next, the transferred toner image 9 is transferred onto the recording paper 10 by nipping the heating roller 6a and the pressure roller 6b.
Settles in. Then, the cleaning means 7 is brought into contact with the recording body 1 to remove the toner particles not transferred to the recording paper 10 and remaining on the latent image recording medium from the latent image recording medium. After that, the charge eliminating means 8 is formed on the entire surface of the latent image recording medium of the recording body 1.
The charge having the opposite polarity to that of the charging means 3 is uniformly applied by the.
As a result, it is possible to suppress the deterioration of the latent image due to the polarization reversal due to the excess charge applied by the charging unit 3.

In this way, a large number of high-quality printed matter can be produced by repeating a series of printing processes of repeating charging → development → transfer → fixing → cleaning → static elimination a desired number of times. At this time, the surface potential difference between the image portion and the background portion of the latent image recording medium immediately before the developing means 4 was measured each time each printing process was performed. As a result, the surface potential difference was maintained at a constant value of about 300 V up to 1,000 times. Was there.

When the production of the desired number of printed matter is completed, the charging means 3 is used to uniformly apply an electric charge to the entire surface of the latent image recording medium of the recording medium 1 so that the internal potential of the latent image recording medium is equal to or higher than the coercive electric field. The latent image recording medium is initialized by charging so that an electric field is generated and aligning the polarization state. As a result, the recording body 1 is
The latent image already written on the latent image recording medium is erased,
A new latent image can be written on the latent image recording medium.

It is also possible to change the voltage applied by the charging means 3 in each of the latent image forming process and the printing process to set the surface potential of the latent image recording medium to the optimum condition.

[0047]

As is apparent from the above description, claim 1
According to the fifth aspect of the invention, since the ferroelectric latent image recording medium is charged before development, the surface potential difference between the image portion and the background portion of the latent image recording medium can be amplified. For this reason, it is possible to perform high-density development in the image area and prevent the toner particles from adhering to the background area, so that it is possible to prevent deterioration of image quality such as white background stains. Further, in the inventions of claims 1 and 5, the latent image formed on the latent image recording medium by the charging process can be erased, so that the latent image is rewritten and the latent image recording medium is repeatedly used. You can

Here, in the inventions of claims 2 and 6, since the charges are uniformly applied to the latent image recording medium, the surface potential difference between the image portion and the background portion of the latent image recording medium is made uniform. Can be amplified to. In the inventions of claims 3 and 4 and claims 7 to 9, the latent image recording medium is neutralized by uniformly applying a charge having a polarity opposite to that at the time of charging after the transfer step and before the subsequent subsequent charging step. Therefore, even when performing very high-speed printing, the surface potential difference between the image portion and the background portion of the latent image recording medium can be kept constant, and a retention copy that repeatedly obtains the same printed matter from one latent image. However, it is suitable to keep the image quality constant.

According to the tenth and eleventh aspects of the present invention, since the latent image recording medium is made of ferroelectric ceramics or polymer, the latent image recording medium can be produced by a well-known existing method.

[Brief description of drawings]

FIG. 1 shows an embodiment of a recording apparatus to which a recording method of the present invention is applied, and is a front view showing a schematic configuration of the recording apparatus.

FIG. 2 is a DE characteristic diagram showing a relationship between an electric displacement (D) and an electric field (E) for explaining a mechanism of surface potential difference generation at the time of charging and discharging in an image portion and a background portion of a latent image recording medium. Is.

[Explanation of symbols]

 1 Recording Medium 2 Latent Image Forming Means (Multi Stylus) 3 Charging Means (Corona Charger) 4 Developing Means 4a Developer Tank 4b Developing Roll 5 Transfer Means 5a Transfer Roll 5b Bias Power Supply 6 Fixing Means 6a Heating Rolls 6b Pressure Rolls 7 Cleaning means 7a Sponge roll 7b Blade 8 Charge eliminating means (corona charger) 9 Toner image 10 Recording paper

Claims (11)

[Claims] 1. A latent image forming step of forming a latent image based on print information on a ferroelectric latent image recording medium, a developing step of developing the latent image into a visible image, and the visible image. A recording step of transferring the recording medium onto a recording medium, and a charging step before the developing step. 2. The recording method according to claim 1, wherein the charging step uniformly applies an electric charge to the latent image recording medium. 3. The recording method according to claim 1, further comprising a charge eliminating step after the transferring step and before the subsequent subsequent charging step. 4. The static elimination step uniformly applies an electric charge having a polarity opposite to that of the charging step to the latent image recording medium.
Recording method. 5. A recording body having a ferroelectric latent image recording medium, latent image forming means for forming a latent image based on print information on the latent image recording medium, and a visible image by developing the latent image. And a transfer unit that transfers the visible image onto a recording medium, and a charging unit is provided between the transfer unit and the developing unit. 6. The recording apparatus according to claim 5, wherein the charging unit is a corotron type charger. 7. The recording apparatus according to claim 5, further comprising a discharging unit between the transfer unit and the charging unit. 8. The charge removing unit is a charger.
Recording device. 9. The recording apparatus according to claim 8, wherein the charge eliminating unit is a corotron charger. 10. The recording apparatus according to claim 5, wherein the latent image recording medium is a ferroelectric ceramic. 11. The recording apparatus according to claim 5, wherein the latent image recording medium is a ferroelectric polymer.