JPH049965A - Transfer type electrostatic thermal recording method - Google Patents

Abstract

PURPOSE:To omit cleaning for removing toner and the destaticization of the toner and to realize a good-quality image with a simple device by transferring a toner image obtained after forming an electrostatically charged image on a specified recording medium and reversely developing it on a recording paper such as a plain paper and makes the medium disposable. CONSTITUTION:As to the electrostatic recording medium 1, an electrostatic recording layer 15 is formed on the surface of a base layer 14 and a conductive layer 16 is formed on a back surface. The medium 1 is taken out from a tray by the use of a supply roller 61 and bitten by the clamping pawl 71 of a platen drum 7, then the surface of the medium 1 is uniformly electrostatically charged by a corona charger 21. The electrostatic latent image is formed on the medium by a thermal head 3 and reversely developed with the toner from a developing roller 41. The recording paper 5 is fed by the roller 62 and the toner on the medium 1 is transferred by the action of a corona charger 22 for transfer. After transfer, both of the medium 1 and the paper 5 are separated and the toner image on the paper 5 is fixed and the medium 1 gets out of the pawl 71 and is ejected. Therefore, one medium is used for one recording paper.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a transfer type electrostatic thermal recording method, and more specifically, an electrostatic charge image is formed on a specific recording medium, and the resulting toner is developed by reversing the image. The present invention relates to a transfer type electrostatic thermal recording method in which an image is transferred to recording paper such as plain paper, and when recording is performed again, a new specific recording medium is supplied.

[Conventional technology]

Various recording methods have been proposed, including (1) providing a resin layer that reduces electrical resistance by heating on an electrically conductive substrate, and electrostatically charging this layer;
A method of forming an electrostatic latent image of an image by irradiating heat rays according to the original image (Japanese Patent Publication No. 35-14722), or (2) placing an electrothermographic material that sufficiently transmits heat rays on the original image to be copied. , after giving an electrostatic charge,
A copying method in which an electrostatic latent image is created by the action of heat rays, reversely developed with dry toner, and then fixed (Japanese Patent Publication No. 38-143)
Publication No. 47), etc. are known. However, these methods still have unresolved problems, such as poor image resolution and high recording energy requirements because infrared rays are irradiated while the document is in close contact with the document.

[Problem to be solved by the invention]

The present invention solves the above-mentioned unresolved problems, and also provides a transfer electrostatic thermal recording method that has a simpler process than conventional techniques and is capable of recording digital information on plain paper. .

[Means to solve the problem]

In the transfer type electrostatic thermal recording method of the present invention, one end of a sheet-like recording medium having an electrostatic thermal recording layer that is chargeable at room temperature and becomes non-chargeable or weakly chargeable under heating is gripped with a clamp claw, and a rotating drum is moved. In this state, the recording medium is uniformly charged, a thermal signal corresponding to the image signal is applied to form a latent latent image, and the charged latent image is charged with toner having the same polarity as the uniformly charged polarity. forming an image on the recording medium by reverse development;
Subsequently, after performing the process of transferring the image onto recording paper as one cycle, the recording medium used in this one cycle is discharged, and a new sheet-like recording medium is supplied for each I-cycle recording. It is characterized by repeating the process.

The present inventors have so far carried out research and examination on various recording media, and found that recording media (electrothermal recording media) that are chargeable at room temperature and become non-chargeable or weakly chargeable under heating. ), it was confirmed that high quality images could be obtained without any troublesome operations. The present invention has been achieved thereby.

In the following, the invention will be explained in more detail with reference to the additional drawings.

First, the electrostatic thermal recording medium used in the present invention has an electrostatic thermal recording layer 15 on the surface of the base layer 14, as shown in FIG.
is formed, and a conductive layer 16 is formed on the back surface of the base layer 14. However, the conductive layer 16 may not be formed if the back surface of the base layer 14 is in contact with a conductive drum or the like. For example, as seen in the apparatus shown in FIG. 3, which will be explained later, if the platen drum 7 is conductive and grounded, the electrostatic thermal recording medium 1 is intentionally provided with the conductive layer 16. It doesn't matter if you don't.

The base layer 14 is a support for the electrostatic thermal recording layer 15.

For example, polyester, polyvinyl chloride, polyethylene,
It is made of a film such as polypropylene (thickness is about 1 to 50R, preferably about 1 to 30IJrn). If this base layer 14 meets the requirements for the electrostatic thermal recording layer 15, the base M14 can also serve as the electrostatic thermal recording layer.

The electrostatic thermal recording layer 15 is a thermoplastic layer having a softening point of 30 to 200°C, preferably 60 to 15°C (thickness of 1 to 15°C).
50 threshold (preferably about 1 to 30 tones), and has an electrical resistance of 101111 Ωcm or more at room temperature and 109 Ωcm or less when receiving a heating signal. Specifically, polyvinyl chloride, cellulose acetate, polyacetal, vinyl chloride-vinyl acetate copolymer, ethylene-
Examples include vinyl acetate copolymers, acrylic polymers, styrene polymers, polyesters, polyamides, polyethylene, polypropylene, fluorinated acrylic-acrylic copolymers, and styrene-acrylic copolymers.

The material for the conductive layer 16 is an AQ vapor deposited layer (100 to 20
00 thickness) and various conductive treatment agents are used, but the third
If the drum 7 shown in the figure is conductive (volume resistance 109Ωcm or less, preferably 106Ωe1m or less),
It can also serve as a base layer. Note that when a recording medium having a conductive layer 16 is used, as shown in FIG.
It is desirable that the back side of the clamp claw 71 be grounded.

The manner in which recording is performed using such electrostatic thermal recording medium 1 will be explained below with reference to FIG.

First, (a) uniform corona charging is applied to the electrostatic thermal recording layer of the electrostatic recording medium 1. (b) Give a digital signal corresponding to the image signal to the thermal head 3. Thermal head 3 is 8
It is preferable to use a serial head or a line head having a high resolution of ~16 dots/mn+. By this heating, the resistance value of the heated electrostatic thermal recording layer decreases and the charge disappears. (C) An image is formed on the electrostatic thermal recording medium 1 by reversal development with toner 4 having the same polarity as that during uniform corona charging. It does not matter whether a one-component dry developer, a two-component dry developer, or a liquid developer is used for development. Next, (d) the toner image is transferred onto recording paper 5 such as plain paper. After the transfer, if a dry toner is used, the toner is heated and fixed, and if a wet toner is used, the liquid (carrier liquid) remaining on the recording paper is dried.

As for the charging operation, as described above, the method using corona discharge provides the most uniform charging, but a roller charging device using a metal roller or a charging device using a conductive brush may also be used.

When charging with a metal roller, one of the rollers should be made of a conductive elastic material, such as synthetic rubber such as silicone, fluorine, or urethane, in order to provide uniform charging to obtain good contact. It is desirable to use a charging device having an elastic roller in which low resistance particles such as carbon are dispersed.

FIG. 3 schematically depicts an example of equipment useful in carrying out the method of the present invention. The sheet recording medium 1 is fed by a supply roller 6
1, it is taken out from the tray and caught by the clamp claw 71 of the platen drum 7. After the surface of the electrostatic thermal recording layer of the recording medium 1 is uniformly charged by the corona charger 21, a thermal signal corresponding to the image signal is applied by the thermal head 3 to form an electrostatic latent image. This electrostatic latent image is formed by the developing roller 4.
Reversal development is performed using toner from 1. On the other hand, the recording paper 5 is conveyed by the supply roller 62 to the surface of the recording medium 1 having the toner image, and the toner on the recording medium 1 is transferred to the recording paper 5 by the action of the transfer corona charger 22.

After this transfer, the recording medium 1 and the recording paper 5 carrying the toner image are
It is separated from Although not shown, the recording paper 5
As mentioned above, the upper toner image is, for example, heat-fixed if it is made of dry toner, or dried if it is made of wet toner. The recording medium 1 is a clamp claw 71
The paper is removed from the paper and ejected.

If this series of steps is considered as one cycle, the ] cycle results in one recording paper 5 for each - number of recording media 1 used.
An image is formed thereon. Therefore, in order to obtain a large number of copies, the cycle described above is repeated according to the number of copies.

In FIG. 3, numeral 31 represents a head driver 63 and a paper ejecting roller, and 64 represents an electrostatic thermal recording medium ejecting roller.

〔Example〕

Examples will be shown next, but the present invention is not limited thereto.

Example 1 A copying machine as shown in FIG. 3 was prepared. Thickness about 40
An electrostatic thermal recording medium consisting of a polypropylene sheet with an AQ vapor deposited layer of about 1000 people thick is sandwiched between the clamp claws of a platen roller and wound around a platen drum, and then charged to a surface potential of -500V, with a surface potential of 8dot/I1m. A character signal is applied with a recording energy of 0.6+sJ/dat using a thermal head, reverse development is performed using a commercially available developer (liquid developer for wet-type copying machines manufactured by Lif Co., Ltd.), and a reverse bias is applied at the transfer section. A transferred image was obtained on plain paper. The recording medium was discharged after use. After recording, the printed area of the electrostatic thermal recording medium sheet was slightly damaged due to the heating and pressure applied to the writing area.
Since the paper was ejected, there was no problem.

〔Effect of the invention〕

According to the present invention, (1) since the sheet-shaped electrostatic thermal recording medium is used for only one recording, toner cleaning, static neutralization, etc. can be omitted; and (2) because the electrostatic thermal recording medium is disposable, There is no deterioration due to the occurrence of wrinkles, etc., and high reliability and high quality images can be easily obtained. Furthermore, the problem of device plurality does not arise.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an example of an electrostatic thermal recording medium according to the present invention. FIG. 2 is an explanatory diagram of an image obtained by the method of the present invention. FIG. 3 is a schematic diagram of an example of an apparatus useful in carrying out the method of the present invention. 1... Electrostatic thermal recording medium (14... Base layer, 15... Electrostatic thermal recording layer, 16
...Conductive layer) 3...Thermal head 4...Toner 5...Recording paper

Claims (1)

[Claims] (1) One end of a sheet-like recording medium having an electrostatic thermal recording layer that is chargeable at room temperature and becomes non-chargeable or weakly chargeable under heating is held with a clamp claw and wound around a rotating drum. A recording medium is uniformly charged, a thermal signal corresponding to an image signal is applied to form an electrostatic latent image, and the electrostatic latent image is reversely developed with a toner having the same polarity as the uniformly charged polarity to form an electrostatic latent image on the recording medium. After forming an image and then transferring the image to recording paper as one cycle, the recording medium used for this one cycle is ejected, and a new sheet-like recording is made for each cycle of recording. A transfer type electrostatic thermal recording method characterized by supplying a medium and repeating the above steps.